The following site loads fine in Fx34.0.5 and Fx35b6, but not Fx36.0a2 build 20141230004009. https://cualerts.dupaco.com/ I see that SSL Labs' site gives this site an F rating for many reasons. However, I don't know what change we've made in Fx36 causes it to stop working. The same site loads in current Chrome, with an error indicating that it uses outdated security settings that may be restricted in the future.

Found during Fx36 SSL compat testing, unsure if related to bug 1084025 or not.

That is a tricky one to diagnose. The site is tolerant of TLS 1.2, but it is intolerant of the handshake if it doesn't include the cipher suite it wants (RC4). It times out, not even sending TCP acknowledgments. If anything, bug 1088915 is the culprit. Given the actual content being served, I'm not sure that I'm all that cut up about losing this site.

IE11 on Win8.1 couldn't connect to the site either (it is loading forever). We should evangelize rather than adding yet another workaround if we really need to see the "Under Construction" page.

The patch for bug 1116891 also "fixed" this.