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Since April we started a new EA agreement with Microsoft and added all of our users to E5 licenses of M365 on top of the E3 licenses they already had - we were told that the E3 licenses would disappear anyway.
We don't know if that is related, however since mid-April we started to have numerous users who find their email attachments to get corrupt in Outlook. Whether it's with Outlook 2016 or 365, and Windows 10 or 11 Pro, the symptoms are always the same: the size of the attachments decrease significantly and they cannot be opened in their usual application (Adobe PDF Viewer, Word, Excel, PowerPoint, etc.).
Attachments in emails are oftentimes received already corrupt and are therefore unusable, sometimes they are good to be viewed or opened, then later on get corrupt. Sometimes
the attachments get corrupt when their related emails get forwarded to other users (who also find corrupt attachments in the emails they received).
We noticed that Outlook sometimes get even in a state where no file can get attached to a new email, or no attachment from a received email can get saved on any drive.
Whenever a user tries to open a corrupt attachment, an error message similar to this appear: "there was an error opening this document. The file is damaged and could not be repaired". No useful details get logged in the Event Viewer, all we see at the time of the error is "An unexpected error has occurred".
We tried the SaRa diagnosis program on some users' workstations with no luck, the SaRa program gets to vanish before the issue is seen again.
We tried to run Desktop Outlook in Safe Mode, the issue has not been seen. We tried to disable all of our add-ins one by one in normal mode, the issue was seen with every add-in being disabled....
We have hundreds of users and are out of ideas. Can you please help.
Using Classic Outlook on Windows for personal email, calendar, and contact management
Locked Question. This question was migrated from the Microsoft Support Community. You can vote on whether it's helpful, but you can't add comments or replies or follow the question.
Our Office 365 version is 2303.
We solved the issue here by deploying the following Known Issue Rollback (KIR) to over a thousand of workstations:
Windows 11, version 21H2: KB5023774 230222_032017 Known Issue Rollback
Windows 10, versions 21H2/22H2: KB5023773 230222_032013 Known Issue Rollback
Hi Stephane,
What is the current version you are on office 365? 2208?
I wait feedback
Thanks.
Stephane,
I just wanted to confirm but did you test the fixes from the June 13th updates and were those not helpful in resolving the issue? If those fixes did not work is your support engineer re-escalating the issue?
Gabriel,
As I said the above mentioned KIRs worked for us. As for the June 13 updates we have not applied them yet. So in a way or another I will not be able to confirm whether they can solve the issue.
We opened a case with Microsoft but this was with the Office365 team. At the end they acknowledged that the issue was related to KB5023773 with the CopyFile API and they said they could not do anything else for us. They said that we need to opened a new ticket with the Windows team if we want to keep on troubleshooting the issue. We did not open a new ticket to re-escalate the issue since we seem out of trouble now.
We can confirm that the problem is not solved after the installation of the patch KB5027215. Our Office version is 32-bit 16.0.15601.20680.