not a big issue but unusual:
I updated a server this morning that hosts very large files, and maybe it's worth mentioning that they are in a secondary folder on a different disk than system.
FMS was previously in 16.
Everything went OK, including the opening of files on server, but when I opened them on Pro, it started doing a consistency check (on client!)
I killed Pro, and replaced the files with a backup I had made before the upgrade (so for once this was useful ), and everything went smoothly.