M365 Copilot desktop app for Mac

Question

DongHeon Lee 20

From this morning M365 Copilot desktop app can't read uploaded document (i.e., word, PDF, and etc..)

Same word & PDF file was working fine with M365 Copilot desktop app yesterday.

BUT, M365 Copilot within the word is working with no issues.

it is only when this same file is uploaded to desktop app of M365 Copilot and the error is

"I tried to open Revolution.docx, but the file content couldn’t be read (it appears empty, corrupted, or in a format I can’t process)."

Is there an issue with M365 Copilot desktop app

DongHeon Lee 20 Reputation points

2026-04-09T06:14:57.26+00:00
This error is also occuring even when,

There is nothing wrong with the file format.

Try uploading it from OneDrive - same result.

Used web based M365 Copilot (tried on https://m365.cloud.microsoft same error)

No Licence issue.

No Account issue.
DongHeon Lee 20 Reputation points

2026-04-09T06:40:42.36+00:00

I also tried other files and both web M365 Copilot and M365 Copilot desktop app can't read any files that I am uploading. (from local folder and OneDrive)

Your answer

DongHeon Lee 20 Reputation points

2026-04-09T06:14:57.26+00:00

This error is also occuring even when,

There is nothing wrong with the file format.

Try uploading it from OneDrive - same result.

Used web based M365 Copilot (tried on https://m365.cloud.microsoft same error)

No Licence issue.

No Account issue.
DongHeon Lee 20 Reputation points

2026-04-09T06:40:42.36+00:00

I also tried other files and both web M365 Copilot and M365 Copilot desktop app can't read any files that I am uploading. (from local folder and OneDrive)