Thanks for posting the question on the Community.
To delete machine agent, you also need to delete the machine associated with your agent from the servers list.
You can do that by these steps:
Click “Servers” tab in the top navigation bar
Select server that is associated with your target machine agent
Please ensure there is NO APM associated with this server
Click “Delete” button
After this, you can delete machine agent.
Also, please ensure no application is associated with your machine agent by looking at “Application” field in your machine agent.
This is documented here: https://docs.appdynamics.com/display/PRO45/Manage+Machine+Agents
If you still have an error by this operation, please follow this solution as well: https://community.appdynamics.com/t5/Knowledge-Base/Delete-abandoned-machine-agent/ta-p/22547
You can do that by these steps from controller:
Please make sure that machine agent is no longer running or reporting.
Create a dummy application from controller UI.
Associate the machine agents that you want to delete to that application.
Delete the dummy app that you have created at step 1.
Let me know if this helped you.
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