After installing or upgrading Windows 2008 Domain Controllers to Symantec Endpoint Protection (SEP) 11.0 RU6 MP3, the servers become unresponsive or appear to be hanging. The servers may still respond to ping requests, but primary server functionalities such as RPC, authentications, replication, shares, etc are no longer possible.
This issue is fixed in Symantec Endpoint Protection Release Update 7 Maintenance Patch 1 (RU7 MP1). Please upgrade to the latest available release of SEP in order to take advantage of this and other enhancements and improvements.
The issue only appears to affect Windows 2008 R2 Domain Controllers and is strictly limited to SEP 11.0 RU6 MP3.