EMS unable to config uninstaller

The error message "Body.installer_id is missing" suggests that there might be an issue with the FortiClient EMS configuration, particularly related to the uninstaller. Check the logs for any additional error messages or warnings that might provide more context for the issue. Make sure that the FortiClient EMS service has the necessary permissions to access the ClientUninstaller directory and its contents. Try restarting the FortiClient EMS service to see if that resolves the issue. As you mentioned, you can try to generate the uninstaller packages on another server and then import them into the problematic server. Make sure the packages are compatible with the version of FortiClient EMS you are running . Ensure that the FortiClient EMS version is compatible with the FortiGate and FortiClient versions you are using.

Sounds like you've connected your personal computer to their EMS. In which case your IP, computername, username and the join date is already in the system. They know you did it. Just come clean and have them remove it from your PC.