I`ve got this problem, Log in to Admin or any Supervision console dose take long time about 2-5 minutes to complete log in after that time I can see menu and no problem.
This problem occurs even I have a fresh install no matter log in from internal network (LAN) or over Internet, also no matter which supervisor users.
After entering User& Pass to log in I have to wait much time and see this browser loading circle
But very strange I have no problem with any agent. log in to agents` console are OK( speed of loading first time is well).