We are running Firefox 31 32 and 33 on different machines on windows/XP (updated until end of support). Our router has an expired certificate. On the machines updated to Firefox 32 or above the security popup screen does not show. Instead we just get the corresponding error message, when trying to access the router's homepage. I looked at the support thread "Secure Connection Failed- can not confirm security exception (since update to 31)" . The posted solutions do NOT work! Chrome and even IE work fine. Please take a look at what was changed and reverse it. Or add a possibility to configure exceptions to the always accessible options tab "security", Having only 262 users with the same problem, means all others having the problem just moved to other browsers. For someone using Firefox since the beginning and liking it this will be a hard step, so I raise the issue again. No, buying a new router is NOT an option, because it manages our network storage and printers and the rule is "never fix a running system".