Why isn't Office sending the OPTIONS request to my WebDav server?

Question

Why isn't Office sending the OPTIONS request to my WebDav server?

Kate Glickman 1

We have implemented a WebDav server in our product using the following protocol

https://learn.microsoft.com/en-us/openspecs/office_protocols/MS-OCPROTO/2d268a23-420b-4339-8c56-9e4f8a924171

In step 1 of the spec, it says "The protocol client sends an HTTP OPTIONS request to the folder that contains the file..."

We have a customer who is trying to use this integration in our product. It works fine in one of their environments but does not work in their other environment. They are using the same client machine in both cases. The Fiddler log shows that the OPTIONS request is never happening in the non-working case.

In the past, we've seen issues when there is something wrong with the certificate. However, we have compared the certificates in the two environments and have not found a problem.

Is there another reason why the OPTIONS request would not be sent to the server?

KristianSmith-MSFT 451 Reputation points Microsoft Employee Moderator

2025-08-11T22:07:46.0866667+00:00

Hi Kate,

Thanks for reaching out with your MS-OCPROTO question. One of our engineers will research this and follow-up with you soon.

Regards,
Kristian S
Support Escalation Engineer
Microsoft Open Specifications
Mike Bowen 2,056 Reputation points Microsoft Employee Moderator

2025-08-12T20:54:17.7333333+00:00
Hi @Kate Glickman ,

I will investigate this for you. To help my investigation, could you please answer the following questions:

Your product is the WebDav server and your customer is trying to connect to it from their client's environment. Is that correct?

You mentioned in the failures the Fiddler logs show that the OPTIONS request is not sent. Was anything sent? Can you share the logs for the success and failure? If you can share them, please email them to [email protected] and mention my name or post a link to them here.

What is the difference between the two environments? e.g. one is prod the other dev, or one is using Windows and the other MacOS, etc.

Has your customer tried any other environments? If so, what was the result?

Is it possible your client's environment is blocking the OPTIONS request? e.g. could it be blocked by an enterprise firewall, web filter or antivirus?

Please let me know if there are any other details you think would help with my investigation.

Best regards,

Michael B

Sr. Escalation Engineer

Microsoft Open Specifications
Kate Glickman 1 Reputation point

2025-08-13T11:17:10.58+00:00

Your product is the WebDav server and your customer is trying to connect to it from their client's environment. Is that correct?

Yes, out product implements the WebDav server and the customer is trying to connect to it from their Windows machine with a locally installed version of Office. The user clicks on a link that uses an MS Office protocol (i.e. ms-word:ofe|u|https:op.mycompany.com ...)

You mentioned in the failures the Fiddler logs show that the OPTIONS request is not sent. Was anything sent? Can you share the logs for the success and failure? If you can share them, please email them to [email protected] and mention my name or post a link to them here.

No, nothing was sent in the failure case. I will try to get you the Fiddler logs for the success case. I will need to get permission and figure out the logistics. I don't believe that they contain sensitive information but we have restrictions on things like this. Is there a more secure way I can send them?

What is the difference between the two environments? e.g. one is prod the other dev, or one is using Windows and the other MacOS, etc.

Has your customer tried any other environments? If so, what was the result?

It works in Prod and fails in Dev for an older release. Now it's failing in UAT for our new release but we have not made any changes to this feature.

Is it possible your client's environment is blocking the OPTIONS request? e.g. could it be blocked by an enterprise firewall, web filter or antivirus?

That is always my first thought. It would explain why we're not seeing anything in our own logs. However, I would expect to see failed requests in the Fiddler log and I'm not seeing any requests after an initial request that comes from the browser to the server to initialize things.
Kate Glickman 1 Reputation point

2025-08-13T19:24:23.96+00:00

I can not get the Fiddler logs in the success case due to various access issues. I can get you logs for an unrelated working test system but I don't think it will be helpful to compare them because in the non-working case, we aren't getting any requests at all.
Mike Bowen 2,056 Reputation points Microsoft Employee Moderator

2025-08-13T19:47:59.0966667+00:00

I don't believe that they contain sensitive information but we have restrictions on things like this. Is there a more secure way I can send them?

Yes, email [email protected] and mention my name and I will send instructions for sharing the files.

Can you try accessing the same URL via Edge (since Office and Explorer use WinINet) or use net use * https://yourserver/path to test from the command line. And let me know the results.

It could also be an issue with name resolution or proxy misconfiguration. Please run nslookup yourserver, ping yourserver to verify DNS. And check proxy settings: netsh winhttp show proxy or Internet Options → Connections → LAN Settings

Also, make sure that the WebClient service is running: run services.msc → Ensure WebClient is running and set to automatic.

We should also check your WebDav connection in general in the failing environment. Run PowerShell as administrator and run net use Z: https://yourwebdavserver.com/path /user:yourusername yourpassword and let me know the results.

Please give that a shot and let me know the results.

Best regards,

Michael B

Microsoft Open Specifications
Kate Glickman 1 Reputation point

2025-08-13T21:40:15.12+00:00
The url works fine via browser. I don't know which browser they tried but it was probably Edge or Chrome.

Since the URL works from a browser, can we assume that it's not a DNS or proxy issue?

I don't think it can be an issue of the WebClient service not running since it works from the same machine to a different WebDav server.

I don't the net use will work since we haven't implemented basic auth.
Mike Bowen 2,056 Reputation points Microsoft Employee Moderator

2025-08-15T22:34:49.7333333+00:00

Hi @Kate Glickman,

Please clarify a few things to make sure I'm investigating this issue correctly:

The Fiddler traces you took are from your WebDav server, is that right?

If the Fiddler traces are from the WebDav server, can you get traces from the client?

The prod, dev, and uat environments are referring to your WebDav server, the client environment doesn't change, correct?

Thanks, Michael B
Kate Glickman 1 Reputation point

2025-08-15T22:42:46.1733333+00:00

Sorry, I guess I was unclear.

The Fiddler traces you took are from your WebDav server, is that right?

No, it's the Fiddler traces from the client that are showing no options request. That's why I don't think it's a firewall or DNS issue, etc.

The prod, dev, and uat environments are referring to your WebDav server, the client environment doesn't change, correct?

Correct.
Mike Bowen 2,056 Reputation points Microsoft Employee Moderator

2025-08-18T20:43:50.0033333+00:00
Hi @Kate Glickman ,

Thanks for the update, a few more questions:

Are the URLs for the successful request the same or different? Can you share the full URLs?

Does your WebDAV server use IIS, an Apache server, something else?

How are your environments setup? Are the dev, prod, and uat servers on the same or different machines? Are they virtual?

Also, please retrieve the logs from Office Word for the failed Options request/trying to connect to WebDAV). To do that, on the client machine, please download Diagnostic Data Viewer then repro your scenario and follow the instructions there and here (Using the Diagnostic Data Viewer with Office to get the log.

Best regards,

Michael B
Gargi Samaiya 0 Reputation points

2025-08-21T13:11:09.29+00:00

Hi Mike ,

We are finally able to enable the View Diagnostic Data option in Windows settings; however, our customer is unable to install the Diagnostic Data Viewer.

The current challenge is that they don’t know where the diagnostic log files are stored. Would you know what would be the exact folder location?

Regards

Gargi
Mike Bowen 2,056 Reputation points Microsoft Employee Moderator

2025-08-21T20:16:27.67+00:00
Hi @Gargi Samaiya ,

The location of the diagnostic log files is not user-accessible and is designed to protect the integrity and privacy of the diagnostic data. To view the logs you will need to install the Diagnostic Data Viewer. Here are the instructions for that:

Enable Data Viewing:

Go to Start > Settings > Privacy & security > Diagnostics & feedback

Under View diagnostic data, toggle Turn on Diagnostic Data Viewer to On

Install the App:

Click Open Diagnostic Data Viewer

This opens the Microsoft Store

Click Install to download the app

Launch the App:

You can open it from the same settings page or search for Diagnostic Data Viewer in the Start menu

Enable Office Diagnostic Data (Optional):

In the DDV app, go to Settings

Enable Office diagnostic data viewing if you want to see Office-related logs

Export to CSV:

In DDV, use the Export feature to save the data as a .csv file

The exported file includes diagnostic event names in Column B

Please let me know if you have any questions.

Best regards,

Michael B
Gargi Samaiya 0 Reputation points

2025-08-22T07:31:02.0433333+00:00

Hi Michael ,

Due to internal policies, our customer is unable to install the "Diagnostic Data Viewer" on their machine.

Is their any alternative approach ?

Thanks

Gargi
Gargi Samaiya 0 Reputation points

2025-08-22T14:03:29.8333333+00:00

Hi Michael,

I am writing to follow up regarding my query above .

Thanks

Gargi
Mike Bowen 2,056 Reputation points Microsoft Employee Moderator

2025-08-22T19:23:03.6966667+00:00

Hi Kate & Gargi,

Can you share a screenshot or even better a video of the failure scenario in Word?

Are the URLs being used for the success and failure scenarios the same? Can you share the URLs?

Have you tested this with a different client? If so, what were the results?

Also, I think that a call might be helpful here. Please email [email protected] and mention my name and I will set up a meeting for next week.

Best regards,

Michael B
Kate Glickman 1 Reputation point

2025-08-22T22:56:57.61+00:00

Response sent via email.
Gargi Samaiya 0 Reputation points

2025-09-11T06:13:21.1133333+00:00
Hi Mike ,

The core issue was due to the OPTIONS, LOCK, and UNLOCK HTTP methods being blocked. Allowing these methods through has addressed the primary cause of the problem.

Now the issue is - when customer is trying to edit the xlsx file (Office 2016) they are getting this warning in non-prod:

UPLOAD FAILED We're sorry, someone updated the server copy and it's not possible to upload your change now. [Keep My Version] [Keep Server Version]

But on the same computer same in Prod this warning is not coming

We tried below options but no luck

1)Clear the Cache:

Open Word or Excel and go to File > Account.

Click on Settings or the gear icon, and then click "Delete cached files" under Cache Settings.

You may also want to check the box to "Delete files from the cache after closing the document" to prevent future issues.

User is not logged in a OneDrive account.

3)Sign Out and Back In:

In your Office app, go to File > Account.

Click "Sign out" from any accounts.

Then, sign back in with your correct work or Office 2016 account.

Any suggestions on how we can overcome this warning ?
Obaid Farooqi MSFT 771 Reputation points Microsoft Employee Moderator

2025-09-11T17:49:27.8866667+00:00

Hi Gargi Samya:

I have alerted the open specifications team regarding your inquiry. A member of the team will be in touch soon.

Regards,

Obaid Farooqi - MSFT
Mike Bowen 2,056 Reputation points Microsoft Employee Moderator

2025-09-11T19:49:23.3266667+00:00
Hi Gargi,

I see that you have tried clearing the Word and Excel caches, but please also follow the steps here (https://support.microsoft.com/en-us/office/delete-your-office-document-cache-b1d3765e-d71b-4bb8-99ca-acd22c42995d) to delete the full Office document cache.

If that does not resolve the issue, reproduce the error and then check the Windows Event Viewer for Office/Network and check Windows Logs > Application and System for errors from Office, WebClient, or network components at the time of the test.

Since you mentioned you can't install anything, please follow these steps to take a network trace with the built in Netsh:

Open an elevated Command Prompt

Start a trace:

netsh trace start capture=yes tracefile=%userprofile%\Desktop\nettrace.etl

Reproduce the Office/WebDAV issue (try to save a file from Excel to the WebDAV server)

Stop the trace:

netsh trace stop

email [email protected] and mention my name and I will send upload instructions for our secure file share.

upload the resulting .etl file to our secure upload.

Best regards,

Michael B
Gargi Samaiya 0 Reputation points

2025-09-15T10:02:38.6633333+00:00

Hi Michael,

Thanks for your suggestion .

But our customer already deleted the full MSOffice document cache, but the error persists.

Additionally, checking the Event View, there is no error at that time when I reproduce the error.

Regarding "netsh trace"they are not able to run it due to not Administrator in the computer, I have asked them if they can reach out to admin who can help .

We also notice Upon removed opening in "Protected View" this warning is not happening in non Prod . To elaborate a bit on this - Due to security restrictions, everybody have "Protected View" enabled, I mean, every MSOffice opened, first it's opened in "Protected View" enabled (a yellow message is displayed in Excel when opening). Clicking on "Edit" we are able to modify this Excel file but, when saving changes in Excel but saving in server, the "Upload failed" warning happens.

Changing setting in Excel application ( File - Options - Trust Center - Trust Center Setting - Protected View) and unchecking all check buttons there. If I repeat tests with this conditions (Editing and attachment in our application), Customer can save the changes properly, without warnings in Non-Prod.
Mike Bowen 2,056 Reputation points Microsoft Employee Moderator

2025-09-15T18:05:56.77+00:00
Hi @Gargi Samaiya ,

Thanks for the information about protected mode, that helps point us in the right direction. To continue our investigation, please answer a few more questions:

Do you see the same error when you open and save files from your non-prod WebDAV server in PowerPoint and/or Word also?

Does this happen with all files saved to your WebDAV server or only one or a few files?

Does this happen if the user creates a new file?

Can you take Fiddler traces on your WebDAV server when the error happens and share them?

Best regards, Michael Bowen
Gargi Samaiya 0 Reputation points

2025-09-17T08:49:38.8766667+00:00

Hi Mike ,

we have been testing deeply and this this the current situation:

WITH "Protected View" enabled in Microsoft Office suite:

PROD:

· All documents are properly opened and saved (docx, xlsx and pptx)

UAT: ·

· All .pptx documents are properly opened and saved

· Most of .docx documents are displaying Upload failed error when saving, but some others are saving ok. (We were trying to figure out a special pattern or type of document that produce error, and it seems to happen when the document is bigger than one page )

· All .xlsx documents are displaying Upload failed error when saving

DEV:

· Most of .pptx documents are displaying Upload failed error when saving, but some others are saving ok. (We were trying to figure out a special pattern or type of document that produce error, but I'm no able to determine that)

· Most of .docx documents are displaying Upload failed error when saving, but some others are saving ok.

· All .xlsx documents are displaying Upload failed error when saving

WITHOUT "Protected View" enabled in Microsoft Office suite:All documents are properly saved in all environments.

The main point it's due to security policy we can't disable Protected View in MS Office suite.

It has the same behaviour whatever the origin of the document; a new one and an existing document produces the same result.

Regarding Fiddler , customer can't install it . Thanks

Gargi
Mike Bowen 2,056 Reputation points Microsoft Employee Moderator

2025-09-17T22:40:31.6766667+00:00
Hi Gargi,

Please answer/confirm a few questions for me, so that I am sure that I understand your situation correctly.

You said that you have Dev, UAT, and Prod environments. How are you hosting them? Are they under your control or are they developed by your customer and under their control?

How are you testing the different environments and scenarios? Is your customer attempting to open a file from your WebDAV server from the different environments? Or are you testing from your own machine?

Can you reproduce the issue with your own client machine that you control and take traces on that machine?

Do any other customers have the same problems?

Thanks!

Michael
Gargi Samaiya 0 Reputation points

2025-09-30T10:05:46.0966667+00:00

Hi Michael,

I’ve spent a couple of hours trying to install Diagnostic Data Viewer on my VM, but I keep running into the same error. I’ve tried running the .exe file manually, installing the app directly from the Microsoft Store, and even updating my browser, but no luck—each time the same error appears.

Can you help me how can get this fix ?

Thanks

Gargi
Mike Bowen 2,056 Reputation points Microsoft Employee Moderator

2025-09-30T19:50:37.1266667+00:00

Hi Gargi,

Thanks for the update. From your screenshot, it looks like you are using Internet Explorer. Can you try using a modern browser such as Edge or Chrome?

Also, the Diagnostic Data Viewer is a good way to take traces, but if you can install Fiddler on both the client and server and then repeat the scenarios while taking traces that could tell us a lot too.

Best regards,

Michael
Gargi Samaiya 0 Reputation points

2025-10-03T06:16:38.0366667+00:00

Hi Michael ,

I have managed to capture Fiddler traces from UAT client system.

But on server we wont be install anything .

Will that help ?

Thanks

Gargi
Mike Bowen 2,056 Reputation points Microsoft Employee Moderator

2025-10-03T22:14:32.1133333+00:00

Hi Gargi,

Please email [email protected] and I will send you instructions for uploading files to our secure file share.

Thanks,

Michael

1 answer

Your answer

KristianSmith-MSFT 451 Reputation points Microsoft Employee Moderator

2025-08-11T22:07:46.0866667+00:00

Hi Kate,

Thanks for reaching out with your MS-OCPROTO question. One of our engineers will research this and follow-up with you soon.

Regards,
Kristian S
Support Escalation Engineer
Microsoft Open Specifications
Mike Bowen 2,056 Reputation points Microsoft Employee Moderator

2025-08-12T20:54:17.7333333+00:00

Hi @Kate Glickman ,

I will investigate this for you. To help my investigation, could you please answer the following questions:

Your product is the WebDav server and your customer is trying to connect to it from their client's environment. Is that correct?

You mentioned in the failures the Fiddler logs show that the OPTIONS request is not sent. Was anything sent? Can you share the logs for the success and failure? If you can share them, please email them to [email protected] and mention my name or post a link to them here.

What is the difference between the two environments? e.g. one is prod the other dev, or one is using Windows and the other MacOS, etc.

Has your customer tried any other environments? If so, what was the result?

Is it possible your client's environment is blocking the OPTIONS request? e.g. could it be blocked by an enterprise firewall, web filter or antivirus?

Please let me know if there are any other details you think would help with my investigation.

Best regards,

Michael B

Sr. Escalation Engineer

Microsoft Open Specifications
Kate Glickman 1 Reputation point

2025-08-13T11:17:10.58+00:00

Your product is the WebDav server and your customer is trying to connect to it from their client's environment. Is that correct?

Yes, out product implements the WebDav server and the customer is trying to connect to it from their Windows machine with a locally installed version of Office. The user clicks on a link that uses an MS Office protocol (i.e. ms-word:ofe|u|https:op.mycompany.com ...)

You mentioned in the failures the Fiddler logs show that the OPTIONS request is not sent. Was anything sent? Can you share the logs for the success and failure? If you can share them, please email them to [email protected] and mention my name or post a link to them here.

No, nothing was sent in the failure case. I will try to get you the Fiddler logs for the success case. I will need to get permission and figure out the logistics. I don't believe that they contain sensitive information but we have restrictions on things like this. Is there a more secure way I can send them?

What is the difference between the two environments? e.g. one is prod the other dev, or one is using Windows and the other MacOS, etc.

Has your customer tried any other environments? If so, what was the result?

It works in Prod and fails in Dev for an older release. Now it's failing in UAT for our new release but we have not made any changes to this feature.

Is it possible your client's environment is blocking the OPTIONS request? e.g. could it be blocked by an enterprise firewall, web filter or antivirus?

That is always my first thought. It would explain why we're not seeing anything in our own logs. However, I would expect to see failed requests in the Fiddler log and I'm not seeing any requests after an initial request that comes from the browser to the server to initialize things.
Kate Glickman 1 Reputation point

2025-08-13T19:24:23.96+00:00

I can not get the Fiddler logs in the success case due to various access issues. I can get you logs for an unrelated working test system but I don't think it will be helpful to compare them because in the non-working case, we aren't getting any requests at all.
Mike Bowen 2,056 Reputation points Microsoft Employee Moderator

2025-08-13T19:47:59.0966667+00:00

I don't believe that they contain sensitive information but we have restrictions on things like this. Is there a more secure way I can send them?

Yes, email [email protected] and mention my name and I will send instructions for sharing the files.

Can you try accessing the same URL via Edge (since Office and Explorer use WinINet) or use net use * https://yourserver/path to test from the command line. And let me know the results.

It could also be an issue with name resolution or proxy misconfiguration. Please run nslookup yourserver, ping yourserver to verify DNS. And check proxy settings: netsh winhttp show proxy or Internet Options → Connections → LAN Settings

Also, make sure that the WebClient service is running: run services.msc → Ensure WebClient is running and set to automatic.

We should also check your WebDav connection in general in the failing environment. Run PowerShell as administrator and run net use Z: https://yourwebdavserver.com/path /user:yourusername yourpassword and let me know the results.

Please give that a shot and let me know the results.

Best regards,

Michael B

Microsoft Open Specifications
Kate Glickman 1 Reputation point

2025-08-13T21:40:15.12+00:00

The url works fine via browser. I don't know which browser they tried but it was probably Edge or Chrome.

Since the URL works from a browser, can we assume that it's not a DNS or proxy issue?

I don't think it can be an issue of the WebClient service not running since it works from the same machine to a different WebDav server.

I don't the net use will work since we haven't implemented basic auth.
Mike Bowen 2,056 Reputation points Microsoft Employee Moderator

2025-08-15T22:34:49.7333333+00:00

Hi @Kate Glickman,

Please clarify a few things to make sure I'm investigating this issue correctly:

The Fiddler traces you took are from your WebDav server, is that right?

If the Fiddler traces are from the WebDav server, can you get traces from the client?

The prod, dev, and uat environments are referring to your WebDav server, the client environment doesn't change, correct?

Thanks, Michael B
Kate Glickman 1 Reputation point

2025-08-15T22:42:46.1733333+00:00

Sorry, I guess I was unclear.

The Fiddler traces you took are from your WebDav server, is that right?

No, it's the Fiddler traces from the client that are showing no options request. That's why I don't think it's a firewall or DNS issue, etc.

The prod, dev, and uat environments are referring to your WebDav server, the client environment doesn't change, correct?

Correct.
Mike Bowen 2,056 Reputation points Microsoft Employee Moderator

2025-08-18T20:43:50.0033333+00:00

Hi @Kate Glickman ,

Thanks for the update, a few more questions:

Are the URLs for the successful request the same or different? Can you share the full URLs?

Does your WebDAV server use IIS, an Apache server, something else?

How are your environments setup? Are the dev, prod, and uat servers on the same or different machines? Are they virtual?

Also, please retrieve the logs from Office Word for the failed Options request/trying to connect to WebDAV). To do that, on the client machine, please download Diagnostic Data Viewer then repro your scenario and follow the instructions there and here (Using the Diagnostic Data Viewer with Office to get the log.

Best regards,

Michael B
Gargi Samaiya 0 Reputation points

2025-08-21T13:11:09.29+00:00

Hi Mike ,

We are finally able to enable the View Diagnostic Data option in Windows settings; however, our customer is unable to install the Diagnostic Data Viewer.

The current challenge is that they don’t know where the diagnostic log files are stored. Would you know what would be the exact folder location?

Regards

Gargi
Mike Bowen 2,056 Reputation points Microsoft Employee Moderator

2025-08-21T20:16:27.67+00:00

Hi @Gargi Samaiya ,

The location of the diagnostic log files is not user-accessible and is designed to protect the integrity and privacy of the diagnostic data. To view the logs you will need to install the Diagnostic Data Viewer. Here are the instructions for that:

Enable Data Viewing:

Go to Start > Settings > Privacy & security > Diagnostics & feedback

Under View diagnostic data, toggle Turn on Diagnostic Data Viewer to On

Install the App:

Click Open Diagnostic Data Viewer

This opens the Microsoft Store

Click Install to download the app

Launch the App:

You can open it from the same settings page or search for Diagnostic Data Viewer in the Start menu

Enable Office Diagnostic Data (Optional):

In the DDV app, go to Settings

Enable Office diagnostic data viewing if you want to see Office-related logs

Export to CSV:

In DDV, use the Export feature to save the data as a .csv file

The exported file includes diagnostic event names in Column B

Please let me know if you have any questions.

Best regards,

Michael B
Gargi Samaiya 0 Reputation points

2025-08-22T07:31:02.0433333+00:00

Hi Michael ,

Due to internal policies, our customer is unable to install the "Diagnostic Data Viewer" on their machine.

Is their any alternative approach ?

Thanks

Gargi
Gargi Samaiya 0 Reputation points

2025-08-22T14:03:29.8333333+00:00

Hi Michael,

I am writing to follow up regarding my query above .

Thanks

Gargi
Mike Bowen 2,056 Reputation points Microsoft Employee Moderator

2025-08-22T19:23:03.6966667+00:00

Hi Kate & Gargi,

Can you share a screenshot or even better a video of the failure scenario in Word?

Are the URLs being used for the success and failure scenarios the same? Can you share the URLs?

Have you tested this with a different client? If so, what were the results?

Also, I think that a call might be helpful here. Please email [email protected] and mention my name and I will set up a meeting for next week.

Best regards,

Michael B
Kate Glickman 1 Reputation point

2025-08-22T22:56:57.61+00:00

Response sent via email.
Gargi Samaiya 0 Reputation points

2025-09-11T06:13:21.1133333+00:00

Hi Mike ,

The core issue was due to the OPTIONS, LOCK, and UNLOCK HTTP methods being blocked. Allowing these methods through has addressed the primary cause of the problem.

Now the issue is - when customer is trying to edit the xlsx file (Office 2016) they are getting this warning in non-prod:

UPLOAD FAILED We're sorry, someone updated the server copy and it's not possible to upload your change now. [Keep My Version] [Keep Server Version]

But on the same computer same in Prod this warning is not coming

We tried below options but no luck

1)Clear the Cache:

Open Word or Excel and go to File > Account.

Click on Settings or the gear icon, and then click "Delete cached files" under Cache Settings.

You may also want to check the box to "Delete files from the cache after closing the document" to prevent future issues.

User is not logged in a OneDrive account.

3)Sign Out and Back In:

In your Office app, go to File > Account.

Click "Sign out" from any accounts.

Then, sign back in with your correct work or Office 2016 account.

Any suggestions on how we can overcome this warning ?
Obaid Farooqi MSFT 771 Reputation points Microsoft Employee Moderator

2025-09-11T17:49:27.8866667+00:00

Hi Gargi Samya:

I have alerted the open specifications team regarding your inquiry. A member of the team will be in touch soon.

Regards,

Obaid Farooqi - MSFT
Mike Bowen 2,056 Reputation points Microsoft Employee Moderator

2025-09-11T19:49:23.3266667+00:00

Hi Gargi,

I see that you have tried clearing the Word and Excel caches, but please also follow the steps here (https://support.microsoft.com/en-us/office/delete-your-office-document-cache-b1d3765e-d71b-4bb8-99ca-acd22c42995d) to delete the full Office document cache.

If that does not resolve the issue, reproduce the error and then check the Windows Event Viewer for Office/Network and check Windows Logs > Application and System for errors from Office, WebClient, or network components at the time of the test.

Since you mentioned you can't install anything, please follow these steps to take a network trace with the built in Netsh:

Open an elevated Command Prompt

Start a trace:

netsh trace start capture=yes tracefile=%userprofile%\Desktop\nettrace.etl

Reproduce the Office/WebDAV issue (try to save a file from Excel to the WebDAV server)

Stop the trace:

netsh trace stop

email [email protected] and mention my name and I will send upload instructions for our secure file share.

upload the resulting .etl file to our secure upload.

Best regards,

Michael B
Gargi Samaiya 0 Reputation points

2025-09-15T10:02:38.6633333+00:00

Hi Michael,

Thanks for your suggestion .

But our customer already deleted the full MSOffice document cache, but the error persists.

Additionally, checking the Event View, there is no error at that time when I reproduce the error.

Regarding "netsh trace"they are not able to run it due to not Administrator in the computer, I have asked them if they can reach out to admin who can help .

We also notice Upon removed opening in "Protected View" this warning is not happening in non Prod . To elaborate a bit on this - Due to security restrictions, everybody have "Protected View" enabled, I mean, every MSOffice opened, first it's opened in "Protected View" enabled (a yellow message is displayed in Excel when opening). Clicking on "Edit" we are able to modify this Excel file but, when saving changes in Excel but saving in server, the "Upload failed" warning happens.

Changing setting in Excel application ( File - Options - Trust Center - Trust Center Setting - Protected View) and unchecking all check buttons there. If I repeat tests with this conditions (Editing and attachment in our application), Customer can save the changes properly, without warnings in Non-Prod.
Mike Bowen 2,056 Reputation points Microsoft Employee Moderator

2025-09-15T18:05:56.77+00:00

Hi @Gargi Samaiya ,

Thanks for the information about protected mode, that helps point us in the right direction. To continue our investigation, please answer a few more questions:

Do you see the same error when you open and save files from your non-prod WebDAV server in PowerPoint and/or Word also?

Does this happen with all files saved to your WebDAV server or only one or a few files?

Does this happen if the user creates a new file?

Can you take Fiddler traces on your WebDAV server when the error happens and share them?

Best regards, Michael Bowen
Gargi Samaiya 0 Reputation points

2025-09-17T08:49:38.8766667+00:00

Hi Mike ,

we have been testing deeply and this this the current situation:

WITH "Protected View" enabled in Microsoft Office suite:

PROD:

· All documents are properly opened and saved (docx, xlsx and pptx)

UAT: ·

· All .pptx documents are properly opened and saved

· Most of .docx documents are displaying Upload failed error when saving, but some others are saving ok. (We were trying to figure out a special pattern or type of document that produce error, and it seems to happen when the document is bigger than one page )

· All .xlsx documents are displaying Upload failed error when saving

DEV:

· Most of .pptx documents are displaying Upload failed error when saving, but some others are saving ok. (We were trying to figure out a special pattern or type of document that produce error, but I'm no able to determine that)

· Most of .docx documents are displaying Upload failed error when saving, but some others are saving ok.

· All .xlsx documents are displaying Upload failed error when saving

WITHOUT "Protected View" enabled in Microsoft Office suite:All documents are properly saved in all environments.

The main point it's due to security policy we can't disable Protected View in MS Office suite.

It has the same behaviour whatever the origin of the document; a new one and an existing document produces the same result.

Regarding Fiddler , customer can't install it . Thanks

Gargi
Mike Bowen 2,056 Reputation points Microsoft Employee Moderator

2025-09-17T22:40:31.6766667+00:00

Hi Gargi,

Please answer/confirm a few questions for me, so that I am sure that I understand your situation correctly.

You said that you have Dev, UAT, and Prod environments. How are you hosting them? Are they under your control or are they developed by your customer and under their control?

How are you testing the different environments and scenarios? Is your customer attempting to open a file from your WebDAV server from the different environments? Or are you testing from your own machine?

Can you reproduce the issue with your own client machine that you control and take traces on that machine?

Do any other customers have the same problems?

Thanks!

Michael
Gargi Samaiya 0 Reputation points

2025-09-30T10:05:46.0966667+00:00

Hi Michael,

I’ve spent a couple of hours trying to install Diagnostic Data Viewer on my VM, but I keep running into the same error. I’ve tried running the .exe file manually, installing the app directly from the Microsoft Store, and even updating my browser, but no luck—each time the same error appears.

Can you help me how can get this fix ?

Thanks

Gargi
Mike Bowen 2,056 Reputation points Microsoft Employee Moderator

2025-09-30T19:50:37.1266667+00:00

Hi Gargi,

Thanks for the update. From your screenshot, it looks like you are using Internet Explorer. Can you try using a modern browser such as Edge or Chrome?

Also, the Diagnostic Data Viewer is a good way to take traces, but if you can install Fiddler on both the client and server and then repeat the scenarios while taking traces that could tell us a lot too.

Best regards,

Michael
Gargi Samaiya 0 Reputation points

2025-10-03T06:16:38.0366667+00:00

Hi Michael ,

I have managed to capture Fiddler traces from UAT client system.

But on server we wont be install anything .

Will that help ?

Thanks

Gargi
Mike Bowen 2,056 Reputation points Microsoft Employee Moderator

2025-10-03T22:14:32.1133333+00:00

Hi Gargi,

Please email [email protected] and I will send you instructions for uploading files to our secure file share.

Thanks,

Michael

Answer 1

Kate Glickman 1

It turns out that our Fiddler was taken in an environment without Word installed and we had been making a lot of assumptions based on it. The problem is a blocked OPTIONS request, the most obvious answer. Sigh.

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Why isn't Office sending the OPTIONS request to my WebDav server?

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