Hello forums. We recently upgraded to 2021 sp2. I am trying to get our vault files upgraded to 2021, using the FVUT (file version upgrade tool). I have used this successfully before in previous SW versions. I have the 2021 version installed, and am logged into the vault as admin, but it will not check in the files after upgrading them. The only error I get is "class not registered". Our VAR has not been able to provide a fix; they have suggested uninstalling/reinstalling FVUT, installing .NET 3.0/3.5.