"Error 14258: Cannot perform this operation while SQL ServerAgent is starting. Try again later."

I saw this error today while i was diagnosing my log shipping issue in which primary and standby servers was not in sync.i checked log but i didn't find anything even Sql agent was running and all jobs was showing as successful.

Then i tried to bounce Agent service on primary node then i got below error:

"Error 14258: Cannot perform this operation while SQL Server Agent is starting. Try again later."

To fix this issue, I tried stopping and then restarting just the Agent
service and it won't start, reporting the same error then my guess was that SQL Server was running in lightweight pooling mode. I set it back to the default of
thread mode.

sp_configure 'allow updates', 1
go
reconfigure with override
go
sp_configure 'lightweight pooling', 0
go
reconfigure with override


And after this change it worked for me..