HTTPS stopped working with IIS express
Did you try the following (posted at the bottom of http://www.hanselman.com/blog/WorkingWithSSLAtDevelopmentTimeIsEasierWithIISExpress.aspx).
"I think by moving the self signed cert from Personal to Trusted Root CA directory causes a problem that SSL stops working after developers reboot their machines. (Don't know how it happens, but it does happen consistently.) I finally get around this issue by export and re-import the self-signed cert into the trusted root directory (instead of simply drag it over). Now my self-signed cert is considered and I don't need to REINSTALL/REPAIR IIS Express every time I reboot the machine. "
for me problem was with port number: my Visual Studio 2013/IIS Express configured app port number was NOT in the range :44300-:44398
full answer about same problem: https://stackoverflow.com/a/24957146/908936