A bug that prevents Access Runtime 365 from being used on Windows 10.

Dear BabybooHN,

Thank you for your reply.

Below are the answers to your questions:

・What exact error message or behavior occurs when attempting to open the Access files on the updated build? (e.g., crashing, visual formatting issues, memory warnings)

⇒A pop-up message appeared saying, “A critical error occurred the last time this document was opened. Do you want to open this document?”

When I tried to open it, either Runtime itself crashed or the file would not open even after waiting.

・Are these .accdb or .accde files, and are they stored locally or on a shared network drive?

⇒ I was opening an .accde file. It is stored locally.

・Which Office update channel is your organization using (e.g., Current Channel, Monthly Enterprise Channel), and what was the specific updated build number installed before the rollback?

⇒ I believe it was the Current Channel

Before the rollback, the build number was 16.0.20326.20100, and I rolled it back to 16.0.20228.20190.

・Does this affect all database files or only specific ones (such as those containing VBA macros or linked tables)?

⇒I haven’t been able to verify that yet.

　I plan to check this the next time I have access to the customer’s device—is there a specific way to verify this?

Dear @test_account

The build information (16.0.20326.20100 on Current Channel) and error message details are very helpful.

Since remaining on the rolled-back build (16.0.20228.20190) is currently working smoothly for your customer, please continue using this build as a temporary workaround for now. Maintaining business continuity for your customer is the priority while we monitor this issue.

Regarding your question about how to verify and test this further during your next session on the customer's device:

When you have access to the device again (or in a controlled test environment with build 16.0.20326.20100 re-applied):

• Test a clean sample file: Create or open a basic, fresh .accdb file (with a simple table and form, no VBA or complex macros). If a simple file opens without crashing, the issue may be specifically tied to compiled VBA code or .accde compilation differences across builds.
• Test .accdb vs .accde: If possible, try opening the uncompiled source .accdb file instead of the .accde file on the updated build. Compiled .accde files depend heavily on internal binary compatibility across Access builds and can trigger crash alerts if compiled in a different version.
• Check Trusted Locations & Security Settings: Ensure the folder containing the .accde file is listed as a Trusted Location in Access options, as security blocks in newer builds can sometimes cause silent crashes during startup.

Since there is currently no official public bug bulletin published for this specific build behavior, I am documenting this feedback and tracking whether similar reports arise with version 16.0.20326.20100.

For now, please keep Office updates disabled on the customer's device (File > Account > Update Options > Disable Updates) to prevent Office Click-to-Run from automatically updating back to the broken build.

Please let me know how your testing goes when you next access the device, or if you notice any other patterns.

Dear @test_account

I hope you’re doing well. I just wanted to check in and see how things are going with the steps I shared earlier. If you ran into any difficulties at any point or if something is unclear, please don’t hesitate to let me know. I completely understand that these processes can sometimes be tricky, and I’m here to make it as easy as possible for you.

Feel free to share any details or questions you might have, I’m ready to listen and assist you further

Dear @BabybooHN

It is highly likely that the customer has purchased the device and will be unable to verify the details.

We will put this issue on hold for now until we receive another inquiry from the customer.

The response is as follows:

• Test a clean sample file: Create or open a basic, fresh .accdb file (with a simple table and form, no VBA or complex macros). If a simple file opens without crashing, the issue may be specifically tied to compiled VBA code or .accde compilation differences across builds. ⇒ I’ll check this the next time I can borrow the device.
• Test .accdb vs .accde: If possible, try opening the uncompiled source .accdb file instead of the .accde file on the updated build. Compiled .accde files depend heavily on internal binary compatibility across Access builds and can trigger crash alerts if compiled in a different version. ⇒ I’ll check this the next time I can borrow a device. When I checked before the rollback, I couldn’t open either the .accde or the .accdb file.
• Check Trusted Locations & Security Settings: Ensure the folder containing the .accde file is listed as a Trusted Location in Access options, as security blocks in newer builds can sometimes cause silent crashes during startup. ⇒ I’ve had this setting configured for some time, so it may not be directly related to this issue.

Thank you for your assistance so far.