I'm having this error on one 2008R2 server. I can install the agent but they won't communicate. I've done the "full agent reinstallation" process and this didn't fix my problem. I tried the MS fixit tools but they won't run on my machine..Anything else I can try? attached are my log files.
I can see where the error is occurring in your logs, but I have a few questions concerning this:
Was the agent ever working previously on this system?
Was a 9.0 agent on the system before and upgraded to 9.1?
Are there any proxy settings in use for the agent to download files? Just thinking there's a possibility of an older cached file for patchinstaller.msi which is where it seems to be failing (when updating/installing the patch engine for the agent).