Microsoft Outlook 365 or other MS 365 apps are dropping suddenly errors

[German]German blog reader Robert contacted me recently by emailed to report that he had run into problems with Outlook and other apps under Microsoft 365 on Windows Server 2016 Terminal Server. Microsoft Outlook, Excel crashes in a certain build, which could be related to an Edge update.

Microsoft Outlook 365 crashes

Robert wrote that he was facing something strange. It's about Microsoft 365 (Build 16.0.18324.20168) and apps like Outlook (or Excel, as he found out later).

If he launches Microsoft Outlook Microsoft Outlook (from Microsoft 365, Current Channel) in the latest version on a customer's WTS (a Windows Terminal Server under Windows Server 2016), an error message appears and Outlook is closed again. It's a German version of Microsoft 365, as you can see on the following screenshot, that says "Microsoft Outlook doesn't work, a problem prevented to execute the program".

If he launches Microsoft Outlook 365 in the suggested safe mode, he receives a more detailed error message.

The message reports, that the file react-native-win32.dll was not found in the specified path. This suggested that something had entered the wrong path or deleted the .dll file. When Robert checked the system, the offending file was found in the correct location and was the same version as on his Windows 10 computer.

That was strange. The only change that the reader could see was an update of Microsoft Edge to version 130.0.2849.142 (official build, stable app, extended channel, 64-bit). Webview2 had not been updated yet, Robert wrote. A new installation, even with freshly downloaded installation files, and a restart of the WTS did not help. The following entry was found in the event log:

Name der fehlerhaften Anwendung: OUTLOOK.EXE, Version: 16.0.18324.20168, Zeitstempel: 0x67782e8d

Name des fehlerhaften Moduls: mso20win32client.dll, Version: 0.0.0.0, Zeitstempel: 0x675b7486

Ausnahmecode: 0x201c24a0
Fehleroffset: 0x001bda04
ID des fehlerhaften Prozesses: 0x2690

Faulting application start time: 0x01db6414ae82343f

Faulting application path: C:\Program Files (x86)\Microsoft Office\root\Office16\OUTLOOK.EXE

Faulting module path: C:\Program Files (x86)\Common Files\Microsoft Shared\Office16\mso20win32client.dll

Report identifier: eefe039c-d007-11ef-bdfe-000c29ac047d

Full name of faulting package:

Application ID relative to faulting package: …

During further diagnostic steps, Robert discovered that Microsoft Excel 365 suddenly stopped working and left the following entry in the Event Viewer.

Faulting application name: EXCEL.EXE, version: 16.0.18324.20168, time stamp: 0x67782fb2

Faulting module name: KERNELBASE.dll, version: 10.0.14393.7513, time stamp: 0x67171aad

Exception code: 0xc06d007e

Error offset: 0x000dd562

Faulting process ID: 0x5f8

Faulting application start time: 0x01db64152e395a8c

Faulting application path: C:\Program Files (x86)\Microsoft Office\root\Office16\EXCEL.EXE

Faulting module path: C:\Windows\System32\KERNELBASE.dll

Report ID: 77c7e2bc-d008-11ef-bdfe-000c29ac047d

Full name of the faulty package:

Application ID relative to the faulty package:

At this point it was clear that an update of a component was causing this error.

A downgrade helps

In a third email, Robert then provided a solution to the problem that had occurred. He managed to install the previous version .20162 of Microsoft 365. Try the following command:

"C:\Program Files\Common Files\microsoft shared\ClickToRun\OfficeC2RClient.exe" /update user updatetoversion=16.0.18227.20162

After that, everything seems to be working again. The reader notes that it looks like the latest Microsoft 365 feature update to build .20168 is faulty and does not work, at least on Windows Server 2016.

Confirmed by Microsoft

Addendum: Microsoft has confirmed that they are investigating the issue in MS Service Health Portal, Message ID MO978220.

Some users' Microsoft 365 applications may be unexpectedly crashing on Windows Server 2016 devices

Problem-ID: MO978220
Affected services: Microsoft 365 suite
Status: Service impairment
Problem type: Note
Start time: Jan 13, 2025, 09:56 MEZ

User impact
Users' Microsoft 365 applications may be unexpectedly crashing on Windows Server 2016 devices.

Scope of impact
Impact is specific to some users who are served through the affected infrastructure.

Current status
13. Jan. 2025, 11:45 MEZ
We're continuing to review service monitoring telemetry to isolate the root cause and develop a remediation plan.
Next update by:
Monday, 13. Januar 2025 14:00 MEZ

A German blog reader pointed to the article Microsoft Outlook 365 wirft plötzlich Fehler und stürzt ab (Windows Server 2016 RDS). This guy confirmed, the issue is caused by an Edge update that changed the file react-native-win32.dll. He was able to use an old version to keep Office 365 to run again. But it's risky to exchange an .dll within a system, especially, if the .dll is from a 3rd party source.