Using 5.6 with latest updates (as of today).
The Server Manager "Collaboration -> User Accounts -> Modify" menu option allows a user to be selectively added/removed from a list of current groups.
If a group name includes a hyphen then the update script appears to be broken:
Pressing the "save" button will remove the user from _all_ groups.
Replacing the hyphen with an underscore or other valid character in the group name will correct the problem.
Could someone please confirm/deny this?
Thanks

R.