Having this issue as well ran into it two or three times now. Figured something got corrupted so I did a repair install and it worked again. Then I did a full uninstall and reinstall and it worked again. It just stopped working yesterday again. Can't keep doing that so I opened a ticket just now. Also added the exceptions when it prompts and verified they were there. Stopping the service and restarting it including a full reboot doesn't help either. I just tried installing V3 on my own machine to try to connect to the server, same error even with the proper URL added. Very odd.