Same situation as you Adam - been having those errors for quite some time on multiple management servers. Recent upgrades to the latest Windows agent on the management server have not solved it. Nor has the latest management server patches - though we've yet to try OMW_000117 that was released this week. Interested. My theory on it was there was a managed node on the server where OMW couldn't determine the OS type, or at least it didn't match any OS type definition that it had. This used to happen for us with W2k8 R2 nodes for example, but I thought that the latest patches had introduced that OS type to the mgmt server.
Has anyone successfully resolved this with HP? We had it for quite some time, we refreshed several servers and it went away. I assumed it was a node messed up in the database and that the node was removed. Now the error is back and I am not over joyed to go back to HP support to resolve. If they create an error in their system shouldn't they have documentation to what it relates to and some proper steps to resolve.
Do not mean to rant but have spent 3 months trying to resolve previously with no luck.
There are several possibilities, the most evident being that you have a mis-match of agent platforms to the nodes you are trying to manage. Check to make sure that your agents are all up to the right version.