Hi @Makarios ,
What kind of browser did you use?
Can you open other Office applications for web?
Did you cannot open OneDrive for web or the OneDrive desktop client?
Try to test with https://onedrive.live.com/about/en-us/signin/
Then you can try to reset OneDrive to help you:
Open a Run dialog by pressing Windows key and R, copy this and paste it into the dialog window, then press OK:
%localappdata%\Microsoft\OneDrive\onedrive.exe /reset
If you see a "Windows cannot find..." message, copy and paste this instead, then press OK.
C:\Program Files\Microsoft OneDrive\onedrive.exe /reset
If you see a "Windows cannot find..." message, copy and paste this instead, then press OK.
C:\Program Files (x86)\Microsoft OneDrive\onedrive.exe /reset
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