I have a boatload of VM's I am missing after upgrading from 5.8.x to 6.0. Could this be a licensing issue? The vcenter registration looks
fine, just when I browse I don't see certain machines.
I had a variety of issues including not being able to see VM names. Almost all my strange issues were resolved by going into Administration, Solutions, VMware vSphere and clicking configure, Manage Registrations, check the box "Use collection credentials" click register and save settings. I am not sure this will work to solve your issue but it sure cleared up my issues.
some KBs to look at -
do you have any alerts? Errors in collector or vsphere adapter logs? tried ftaylor99ftaylor99's suggestion?