how to debug: "Service Unavailable" messages

[busyme]

What would be the best way to debug the "Service Unavailable" error?

• I am running VTM 22.1 community edition,
• having two VS.
• The error 500 shows up randomly
• More errors show up after clearing cookies.
• errors logs do not show anything strange. 
• I have removed the monitor. - did not help.
• the destination node is up and running. 
• "Connect failure - Connection Refused" shows up on random. ( no issues on destination hosts )

[rhenders]

Typically, HTTP 500 errors are generated when a server is unavailable.  Because this is a generic error, I recommend opening up a Technical Support ticket with Ivanti Support to troubleshoot further.