I have an issue with Update Manager and finding it quite difficult to troubleshoot - I'm getting a bit lost because I can't see any obvious errors. I have spent a few days on it and went thru some threads on this forum, but can't figure it out 
Maybe someone can help point me in the right direction?
First of all, everything worked OK before the upgrade.
Now, if I want to scan for software patches, I get a message: "VMware vSphere Update Manager had an unknown error."
Looking at the ESXi logs and Update Manager logs, can't pin-point the issue.
One thing I did notice in the xxxxlog4cpp.log file, I have many entries that complain about IPv6 connectivity. I'm not sure if I had these before. Either way, IPv6 is disabled on Update Manager and vCenter server! So why is it showing up in the log?
is there any command line that I can use to get some more information about the error?
I'm sure my network configuration is OK, IP's and DNS and all that seems to be working OK.
I hope someone can help. Sorry if this info is a bit vague.
Josef