A client reported errors "Class not registered" on several computers when copying files to M-Files using either of these methods:
1) Drag and drop.
2) Right-click on the file in Windows Explorer and use the Save to M-Files option.
After some correspondence with support we learned that .NET 4 as a minimum need to be installed on the client computer.
This has not been a requirement so far (at least the computers have worked fine without it), and no warning was issued during the update from 2015.1 to 2015.2.
So the simple solution is to install the latest version of .NET on your client computer :)
BR,
Karl
