O365 apps crash when opening file from sharepoint. mso20win32client.dll related?

Copper Contributor

Having an issue where every time I try to open an office file from a sharepoint site, the program crashes with no error details.  Looking in Windows Event Viewer, I see something like this:


Faulting application name: EXCEL.EXE, version: 16.0.14931.20724, time stamp: 0x631ab870
Faulting module name: mso20win32client.dll, version: 16.0.14931.20704, time stamp: 0x630f0d94
Exception code: 0x230c5214
Fault offset: 0x000000000023ea9d
Faulting process id: 0x2634
Faulting application start time: 0x01d921290e7dfc7a
Faulting application path: C:\Program Files\Microsoft Office\root\Office16\EXCEL.EXE
Faulting module path: C:\Program Files\Common Files\Microsoft Shared\Office16\mso20win32client.dll
Report Id: 5f2887ff-dd3b-4bf1-9275-8f170a7e8572
Faulting package full name:
Faulting package-relative application ID:


It happens with other office apps too.  All logs contain "Faulting module path: C:\Program Files\Common Files\Microsoft Shared\Office16\mso20win32client.dll".  That dll does not exist in that location.  I found it in a different folder, but copying it over to the first directory (and restarting) didn't help anything.  Opening files from local or shared drives works fine though.  I can also open the sharepoint files in the webviewer with no issue, but when i click "Edit in Excel", it crashes too.  I'm on 64 bit windows and 64 bit O365 (Version 2202 Build 16.0.14931.20704) and can't update to anything newer because this is company approved.  I've done reinstalls and repairs several times too.  Anyone have an idea on what's happening here?

2 Replies
I think I found a fix in this forum.


Please try out the below steps;

Please open word/excel/powerpoint application on user's machine.
Sign out of the application with Microsoft ID.
Navigate to Start menu> Control panel> User profile> Credentials manager> delete all the saved credentials.
Open my computer and navigate to C:/ drive> Users> Username> AppData> Local> Microsoft> Office> 16.0> Delete all folder name ending with Cache.
Open word/excel/powerpoint application and sign-in with Microsoft credentials.

I've been able to open excel, word, and powerpoint file from sharepoint now. Not sure if the credential deletion is necessary. I only deleted the ones corresponding to Office15 and left the 16 ones alone.
Hi, it works for me. Thank you JMuser, you made my day!