An index agent that is disabled cannot be started (if it is stopped) and is not started automatically when its associated Content Server is started. You must first stop the index agent if it is running. Use these instructions to enable a disabled index agent.
To enable a disabled index agent:
Connect to the repository as user who has system administrator or superuser privileges.
Navigate to Administration > Indexing Management > Index Agents and Index Servers.
Select the correct index agent.
If the index agent is running, select Tools > Stop.
Select Tools > Enable.
Confirm that you want the index agent enabled.
The index agent’s status changes to running.
Restart the index agent.