You will encountered this error message when:
- Running DPM 2012 SP1
- Just updated to Update Rollup 3
- Tried to update DPM agents but received an error message “Event ID 301 – The protection agent upgrade failed because the protection agent is not installed on server”
Temporary resolution:- (perform manual update)
a) On each protected server, you need to go to your DPM server. Use UNC Path: \\DPMServer \c$\Microsoft System Center 2012\DPM\DPM\agent\RA\4.1.3415.0\amd64\1033 (if using x64 os)
c) Go to DPM Console and refresh the DPM Agent. You will be getting the status “OK”
That should do the trick while Microsoft come out with a solution on it.