Well I'm at wits end...our resellers are trying to get a grasp on this also...But here it goes a hail mary...
When we create a new project, add worksets and turn it into a central file...we get get errors after a short perios of time. Revit will tell us the project has moved from a UNC path to a drive letter path (we don't use UNC) and then later down the road from a UNC path to a UNC path using an IP address instead of server name. All locations are technically the correct spot because the file hasn't moved.
Along with this users lose the ability to "create new local copy". The option is grayed out. This hapeens on every single project.