Hi @Kishore.B, Thanks for your question on the community. I found a similar post here: https://community.appdynamics.com/t5/Infrastructure-Server-Network/Machine-Agent-Stopped/m-p/38459#M938 The general outcome from that thread is to upgrade the machine agent to the latest version of you are not already. You can grab the latest version here  download.appdynamics.com If you learn anything else from that post or from your own investigation, please do share those learnings with the community back on this post. ... View more

Hi Kishore.B- Can you provide some more clarity around the issue? When did the issue start, was it after a restart? Are you experiencing any specific error messages? For urgent issues such as the AppDynamics controller being down, please note that our 24/7 support team can provide a much faster response and resolution than the community forums: https://help.appdynamics.com/hc/en-us/requests/ ... View more