Hello,
This error has been documented by Microsoft and an official Resolution article has been published.
Please try the next steps:
1.Check recent records from the DPM protection agent (DPMRA) source in the Application event log on <ServerName> to discover why the agent failed to respond.
2.Examine the DPMRA log file for any details about the cause of the crash. The DPMRA log file will be in the format of DPMRA*.errlog (for example, DPMRACURR.ERRLOG) and by default is located in \Program Files\Microsoft Data Protection Manager\DPM\Temp.
3.Make sure that the DPM server is remotely accessible from <ServerName>. If a firewall is enabled on the DPM server, make sure that it's not blocking requests from <ServerName>. For complete details about the necessary ports and recommended firewall configuration, see Configure firewall settings for DPM
4.Restart the DPMRA on <ServerName>. If the service doesn't start, reinstall the protection agent.
Reference: https://learn.microsoft.com/en-us/troubleshoot/system-center/dpm/protection-agent-crashes
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