During logoff, an error message appears notifying the user that the profile failed to fully synchronize. In the Windows Event Log, you can see multiple error messages Here are the events in order. Windows cannot copy file \\?\C:\Users\user.REALM\Favorites to location \\?\UNC\server.domain\profiles\user.V2\Favorites. This error may be caused by network problems or insufficient security rights. DETAIL - The parameter is incorrect. There are numerous other error messages like this one pertaining to different files inside the user profile There are too many profile copy errors. Refer to the previous events for details. Windows will not log any additional copy errors for this copy process. The winlogon notification subscriber <Profiles> is taking long time to handle the notification event (Logoff). The winlogon notification subscriber <Profiles> took 101 second(s) to handle the notification event (Logoff). Windows cannot update your roaming profile completely. Check previous events for more details. The main thing that I've noticed is that all the files that it fails to sync pertain the Internet Explorer. So after logging off and then back in, logins, favorites, etc., are not saved. I have produced this bug on multiple compiled Samba domains.