If there is any change to your Central Administration Default zone or any Public URL added to the AAM for your Central Administration, you will see MOSS-GUID Agent failing with stopped-extension-dll exception in MIISClient.exe.
Little more background about this issue – User Profile sync runs night without any errors in Central Administration. But you may not see any new updates being synced to SharePoint user profiles. Existing user profile data stays put.
After you realize that something is wrong with user profile sync, you start troubleshooting. There isn’t any location most of the people on internet suggest to look at when you are having issues with UPS other than MIISClient. It can be located at System Drive\Program Files\Microsoft Office Servers\15\Synchronization Service\UIShell\MIISClient.exe.
Change to the Central Admin url should be updated in FIMSynchronization Service Manager (MIISClient.exe).
This can be done directly by updating the Connextion Information for Management Agent in MIISClient. But the suggested method of updating this is by Stopping and Staring User Profile Synchronization Service under CA > Systerm Settings > Manager Services on server > select the server running UPSS > Stop and Start by providing farm admin credentials. Start a Full synchronization.