Java error on jenkins while trying to add jenkins agent

Not as far as I can tell. If I am reading the stack trace correctly, the stack trace indicates that the Failed to exec spawn helper is happening on the Jenkins controller. Changes on the agent won’t help.

If the failure is due to a Java upgrade that has happened while the Jenkins controller is running, then I think that means that you should be able to resolve the issue by restarting the Java process that runs the Jenkins controller.