Cannot (re)name a new folder

This problem suddenly appeared today :

Whenever I create a new folder, I can't validate the newly typed name. I get the following message instead :
"the file or folder does not exist"

I can only validate the new folder with the name "New Folder".
Trying to rename it after creation leads to the same error message.

This problem appears wherever i try to create a folder (desktop, drive, existing folder) from the file explorer.
However creating a directory from the command line works fine just as folders automatically created by programs (like winRar).

I've tried with both administrator-level accounts. And I've also looked at permissions (that were not changed, anyway).

I would be very appreciative of any hint or help.