The "My Inventory" screen of vRanger shows the Virtual Center server as disconnected, and cannot connect/enumerate the virtual environment's inventory. Connections to individual ESX(i) hosts work (if using the direct host credentialing method, and port 22 SSH is open).
The vRanger install may have been upgraded with the machine logged-in as the service account, and not the "normal" user logon that is usually used. If this happens, and a new user profile is created (i.e. if the machine has never been logged-into using the service account), the service account's user profile may have a web proxy defined for it, and the web proxy may be blocking/trying to redirect port 443 (SSL) traffic to the Virtual Center. This is not supported in vRanger (the SSL port must remain port 443), and the connection attempts will fail.
1)Logon to the vRanger machine using the account used to run the three vRanger services (check the services.msc MMC if unsure what the account is).
2) Open Internet Explorer while logged-in with the account. Go to Internet Options--->Connections-->LAN settings (this location may vary depending on the version of IE installed on the machine).
3) Make sure NO proxy information is defined, and no proxy server is being used. Also un-check the "automatically detect settings" check-box, in case your particular environment has an automatic proxy script set up.
Other problems may also prevent VC connections from being successful, so this is only one possible solution.