Recently I've updated my SharePoint 2013 SQL Box to 2014 release version.
Everything in SharePoint seems to work as expected except User Profile Synchronization Service.
The service appear in stopped state, and if I try to start it, ULS trace this error:
ILM Configuration: Error 'ERR_CONFIG_DB'
UserProfileApplication.SynchronizeMIIS: Failed to configure MIIS post database, will attempt during next rerun. Exception: System.Configuration.ConfigurationErrorsException: ERR_CONFIG_DB
Fortunatly ther's a SharePoint Fix you can request to solve this issue.
The fix (KB 2760265) can be obtained here.
The installation of the fix is pretty fast and no reboot is required.
Configuration Wizard is not necessary after the installation.
Now you can re-enter your "User Profile Synchronization Service" credential and start the service.
