Office 2021 LTSC - Update not possible - Failer30094-35

Good day

I bought the license on a Swiss auction platform: https://www.ricardo.ch/de/a/office-2021-standard-(2-keys)-1296223882/

Did I make an illegal purchase, or is the seller illegal?

I was promised the Office license I need; the fact that it's Office LTSC is irrelevant. But I want a fully functional Office suite and a legal license.

If you are experiencing issues with updating Office LTSC 2021 and have already tried repairing or reinstalling without success, here are a few steps you can take:

1. Check Update Settings: Ensure that your Office is configured to receive updates from the Office Content Delivery Network (CDN). You can verify this in the settings of any Office app.
2. Manual Update Check: Open an Office application (like Word), go to File > Account > Update Options > Update Now. This will force the Click-to-Run service to check for updates.
3. Use Microsoft Configuration Manager: If you are in an enterprise environment, consider using Microsoft Configuration Manager to manage and deploy updates.
4. Group Policy Settings: If your organization uses Active Directory, check the Group Policy settings to ensure they are not preventing updates.
5. Check for Error Codes: If the update fails, note any error codes displayed. You can search for specific solutions related to those error codes.
6. Contact Support: If none of the above solutions work, consider reaching out to Microsoft Support for further assistance.

These steps should help you troubleshoot the update issue with Office LTSC 2021.

References:

• Update Office Long Term Service Channel (LTSC) 2021
• How updates are different in Office LTSC 2021

Dear Sachwalter René Dürig

Thank you for posting on Microsoft Q&A forum 

I’m really sorry this has been so frustrating when you’ve already gone through every troubleshooting step, including full uninstalls, online repairs, and even manual patches, but the 30094-35 error still blocks Office 2021 LTSC updates. That’s incredibly exhausting, and I truly appreciate your patience. 

-May I know where did you purchase the Office 2021 LTSC key? 

-Have you already opened a case with Microsoft Support?  

-If yes, what did they advise? 

-Could you please share the ticket ID so I can try to investigate further? 

The initial response may not fully address your needs, but it will help me better understand your situation and try to find the root causes. Thank you for your patience while we work through it 

If the answer is helpful, please click "Accept Answer" and kindly upvote it. If you have extra questions about this answer, please click "Comment".   

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Good day

All the suggested steps in the first response were unsuccessful.

-May I know where did you purchase the Office 2021 LTSC key? 

The key was purchased from the company Keys Express (keys.express). I received an invoice and receipt for it. I already described the problem to them, and they said the problem was known, but it wasn't due to the key.

-Have you already opened a case with Microsoft Support?   -If yes, what did they advise? 

I was in a support chat twice today, and they looked at the problem but couldn't help. Once I was referred to the activation number, and the other time to a paid support form.

-Could you please share the ticket ID so I can try to investigate further? 

I did not receive a case number after the chat, or rather, I don't know how to get one.

Thank you all for your help!