Today I noticed the following error at a customer site when I wanted to install the new patch bundle, “Metadata for patch missing”. After a close inspection I noticed VirtualCenter was installed with a different http port number. For VMware Update Manager to work you will have to open up the firewall manually:
esxcfg-firewall -o 81,tcp,out,UpdateManager
(Change the port number, in red, according to the used portnumber for VirtualCenter.)