I just found this morning that there are a lot of critical errors since 9/9/2015 in SharePoint, all of them being the Event ID 6398. Here's the error:
The Execute method of job definition Microsoft.Office.Server.UserProfiles.UserProfileImportJob (ID 9c4b1113-cc57-46e0-83c4-75c1c64f909a) threw an exception. More information is included below.
Operation is not valid due to the current state of the object.
When I go see which job is causing this issue (with the id), it points right toward the
User Profile Service Application - User Profile Incremental Synchronization job. And in fact, when I go see users in SharePoint, I can see that they're not up-to-date since about a week (surely since 9/9/2015).
I tried to search for solutions, but they were more "Disable the faulty job" than anything else and I don't think disabling this job is a solution.
I also found a solution that would be to restart the
SharePoint Timer Service on the server, but I'm quite hesitant about this, since I don't know the impacts of restarting the service (even if I don't think it would cause any problem).
I'm using SharePoint 2013 if it can be of any help.
Is anyone ever faced this problem and maybe have a solution?