Symantec Endpoint Protection Manager WebServer service fails to start with an error: Failed to connect to the server. ErrorCode: 0x80020000
Event Viewer logs indicates the following:
Error: Apache Service
Event ID: 3299
Description: The description for Event ID '3299' in Source 'Apache Service' cannot be found. The local computer may not have the necessary registry information or message DLL files to display the message, or you may not have permission to access them. The following information is part of the event:'The Apache service named', '', 'reported the following error:
>>>', 'AH00444: WARNING: ThreadsPerChild of 3000 exceeds ThreadLimit of 1920 threads, decreasing to 1920. To increase, please see the ThreadLimit directive.', '', '', '', '', ''
The issue has been verified to have caused due to the ThreadsPerChild limit has been changed to value: 3000 leading to the Apache Service Crash.
Revert the ThreadsPerChild and ConnectionsToQueuePerChild values in httpd.conf under "%Program Files(x86)\Symantec\Symantec Endpoint Protection Manager\Apache\Conf\" to default value: 500/permissible limit(s) based on the environment size.
NOTE: Increasing the number of Threads/connections will increase load on the SEPM, so make sure your hardware can handle potentially twice as many clients checking in. If increasing the connections puts too much stress on the SEPM, consider adding another Symantec Endpoint Protection Manager for load balancing purposes.