Here is the complete error message I get:

MARIE GIUSTINIANI 

The error means that Trados Studio tried to upload a file to GroupShare, but the process was cancelled before it finished  (so I have moved this post into a more appropriate forum now we know you are accessing GroupShare).  This can happen for a few reasons:

• The GroupShare server was too slow to respond, and the system gave up waiting.
• The file was too big, or the internet connection was too slow.
• The upload was cancelled automatically, maybe because you closed something or moved on before it was done.
• The system lost connection or the login session expired during the upload.

What you could try:

• Make sure the internet connection is stable.
• Try uploading a smaller file to see if that works.
• Don’t click away or close anything while it’s uploading.

If it keeps happening, the GroupShare server might be having performance issues and may need to be checked by whoever is hosting the Groupshare instance.  It's not a cloud solution, it's an on premise solution managed by whoever you are working for.