I have a very unusual issue where users created with the backend, work fine for a while, but at some point they are not SharePoint Users anymore. ie. their SPUser isn't in the SiteUserInfoList. So in the User Management page, the 'IsInSharepoint' field is no.
The FBAUser is still there, and they can still log in. We have some UserProfile stuff setup, so when accessing the profile, it gives us a Data Not Found error.
I'm sure if I can figure out what's kicking them out of SharePoint, my other issue will go away.
One thing from the logs I've found, which occured when a said user logged in (and may well be the cause) is:
SPClaimsAuthRoleProvider.GetRolesForUserBestEffort() failed to load groups for '0#.f|fbamembershipprovider|xxxxxx': System.NullReferenceException: Object reference not set to an instance of an object. at Microsoft.SharePoint.Administration.Claims.SPClaimsAuthRoleProvider.GetRolesForUserBestEffort(String username).
Can't seem to find much about it on the net. Also, the Profile information still exists, I know this because when I go to the edit user screen in the management section, the modified form which includes profile fields, still pulls in all the info from the profile.
Any help would be much appreciated.