Our vcenter server is using port 444. Is this a problem if I put vcenterhost.domain.local:444? I have tried several different browsers, clearing the ssl cache, reinstalling vcenter on port 443 on a different server.  It just sits there for minutes and then may or may not get an error message. We are running v 1.5 on esxi 5 essentials. we have tried quite a few different things and not sure what else to try.  

In our searching I read of several potential solutions and we have tried all of them.

Adding the plugin site to your trusted locations in your browser, 
Clearing your ssl cache, 
Deleting temporary internet files or
Perhaps having a non standard port like us might be the issue.

 Any ideas?