I have the same issue here. I use teams app in windows pc. I join an online international class, but there are only 2 or 3 people from dofferent country who cannot uploading our assignment. Our trouble is same: our internet connection is okay, our file also
fine, but the teams always stated "There is an error with your file".
I have tried reconnect my internet for several times, rename my doc files, even convert it into pdf, but nothing work though
Fyi i have uploaded 2 assignments before this error happen, and those 2 assignments also has the same trouble but then it fix by itself just a few minutes after. But my last assignment still cannot be uploaded for a long time until past the due date.. It
is so annoying and waste our times. I spend an hour to try to fix this problem. At last, I only uploaded a onedrive link. But still it is unefficient for me because i need to upload to onedrive first..
Please Microsoft, fix this problem.
And by the way it is not the only problem we face in teams. Previously, we (all the student) cannot open the assignment file at all. And we don't know why it fix by itself..