User authentication might fail with an error if the behavior profile contains a reference to a deleted profile. The following message can be found in the log records:
Exception: Sitecore.Exceptions.ItemNotFoundException
Message: The item "Couldn't find a profile with the ID '{37B95E72-8961-4652-AC31-8620DFB91F04}'." was not found. It may have been deleted by another user.
Source: Sitecore.Analytics
at Sitecore.Analytics.Data.BehaviorProfileConverter.Convert(IBehaviorProfileContext source)
at Sitecore.Analytics.Pipelines.InitializeInteractionProfile.CopyProfiles.Process(InitializeInteractionProfileArgs args)
...To resolve the issue, download and install the patch compatible with the affected product version found on the following page:
https://github.com/SitecoreSupport/Sitecore.Support.163109/releases
To get a solution for other releases, contact Sitecore Support.