Just something I ran into recently, figured I would post it for those who don't want to search hard for an answer, if they run into it. VS wanted me to sign in to re-validate that infamous 90 day free trial license, wouldn't let me click on anything else, when I started VS up, but the sign in screen was blank. Hadn't encountered this before after all these years, took me awhile to find a solution.
Control Panel > Internet Options > Security
Simply lower the security for internet/local zones. (you can change it back after). An article mentioned to just reset them to default, but mine were already on default settings.
