I'm getting prompted to confirm security certificates that cannot be verified. When I click on "I understand the risks" and Add Exception, I can get the certificate and view the certificate, but the window does not respond when I try to click on "Confirm Security Exception". If I clear the "Permanently store this exception" check box, the window closes, but just kicks me back to the Untrusted Connection page. This is happening for sites for which I know I have previously added exceptions.

I have updated FF to 40.0.3 and get the same issue in safe mode.