Firefox Nightly has the continue button regardless, but if the site has HSTS, it will tell you so, and will not allow you to add an exception; continue only sho

Firefox Nightly has the continue button regardless, but if the site has HSTS, it will tell you so, and will not allow you to add an exception; continue only shows the cause of the problem, in this case, that the certificate came from an untrusted source. This is in line with the "no user recourse" section of the HSTS RFC.