A2A has been installed on a server, but the following error occurs in the logs when trying to start it.
PAM-CM-0603: Security exception. Data tampering detected. Request denied.. Key is empty
Privileged Access Manager, all versions
In this case, the issue was occurring because the IP address for the new A2A client matched the IP address for an older A2A client from a different server which is no longer in use.
The older device was deleted from PAM, which allowed the new A2A client to register. If the device is still needed in PAM but the A2A client should be deleted, modify the device and uncheck the A2A option to have PAM delete the A2A client.