SQL SERVER AGENT ERROR The request failed or the service did not respond in a timely fashion 

First when this type error happens,check your agent-view to be able to get some clue about what is going on with
your Sql Server Agent,
In my case,my I could not be able to start my agent,,
The solution is,my agent was running on Network Service,while my MSSQL14.MSSQLSERVER name is running
on Local System
So make sure that both are running on the same system...
if your Sql Server name is running on Local System ?,your Agent should run on Local System as well

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