Paul - thanks for letting us know, and I apologize for the inconvenience. There have been some issues with the beta site this morning, but I have not been aware that it could be affecting SupportNet also. I will pass your issue on promptly so they are aware of it, and also pass on any info I find out in the meantime..
Paul - Just heard back from our SupportNet Ops team. They have seen the issue you are experiencing before. It generally has to do with your company's network/firewall possibly blocking some of the assets required for SupportNet to be fully functional. They suggest contacting your IT department to make sure all the domains listed on the https://supportnet.mentor.com/help/firewall_configuration.html are not blocked by your company's firewall setup.
If that does not resolve the problem, please let me know.