Are you running hardware version 10 VMs?
With the free license you should not upgrade to hardware version 10, stay at version 8 and everything is OK. You can edit settings with 5.5 U1 and vSphere (non-web) client without a problem. I do not run vCenter and web-client either, and with hw version 8 machines everything works fine.
hw version 10 should only be used if you have vCenter running.
That's also what the KB you referred to tells you. It's referring to the web-client and not the (stand-alone) vSphere client.