Hi Nikhil2303,
First of all, I’d like to point out that we don’t recommend changing registry keys on the server (Unless it’s confirmed by Microsoft), since this could cause potential issues and impact our daily work in a production environment. Due to that, I suggest you restore the registry keys into the original values.
About the issues, we will divide it into three parts and try to resolve them one by one:
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Issue one: “Sync from FIMSynchronization Service is not running”
Possible causes/Solutions: Please verify if the FIM synchronization service is running. To do that, please try the following steps:
- Click Start, select Administrative Tools, and then click Services.
- Scroll down and right-click Forefront Identity Manager Synchronization Service, if it’s stopped, please click “start” to run it and change the “Startup type” to “Automatic”.
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Issue two: The error message “RPC Error 8453 : Replication access was denied.”
Possible causes/Solutions: the error message could be caused by multiple factors. To troubleshoot it, please refer to this article: http://technet.microsoft.com/en-us/library/replication-error-8453-replication-access-was-denied(v=ws.10).aspx and try to solve it using the resolutions provided in the article.
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Issue three: the intermittently error message "The credentials of the supplied user <user> do not map to a forest"
Possible causes/Solutions: Since the issue occurs intermittently, it could be related to the DNS caches. Please try refreshing DNS using the following commands in CMD window on the server:
ipconfig /flushdns
ipconfig /registerDNS