After upgrading a system to a newer version and opening Web Client it could happen that a message appears reporting that it is necessary to upgrade the File Cabinet or a Document Tray.
"Content Server version 6.x is not matching the File Cabinet Version; Please upgrade the file cabinet"

First stop Content Server Service from the Service Monitor or from Windows services console, open a cmd window and run the C:\Program Files (x86)\DocuWare\Content Server\DocuWare.Tools.CtServerUpgrader.exe. This is the default path in a 64 bits Operating System. In case you are not running this kind of system or the Content Server is installed in a different path, please use your correct path.