Post OEM Upgrade to 13.5RU03 - Clean-up Agents does not work on Windows

After upgrading the agents from 13.3->13.5 I am trying to run the cleanup task, which is under the Post Agent Upgrade Tasks tab.

The job works successfully on Linux hosts, but fails on Windows hosts - just get the following message under the deleteOldOracleHomes task:

{currentOH=d:\oemagent\agent_13.5.0.0.0, oracleHomes=d:\oemagent\agent_13.3.0.0.0, stepName=deleteOldOracleHomes, agentGuid=3A2B3DE6A034CD834D062C2ADEEAE27F, agtVersion=13.5.0.0.0, agentName=[hostname]:3873, agentUrl=https://[hostname]:3873/emd/main/, isShared=false}

Any ideas?

Thanks

Karl