That error indicates that the router is defaulting to an obsolete encryption cipher which is vulnerable to the "Logjam" attack that was in the news last year. You can disable these old ciphers in Firefox to try to force the device to up its game. Here's how: (1) In a new tab, type or paste '''about:config''' in the address bar and press Enter. Click the button promising to be careful. (2) In the search box above the list, type or paste '''dhe''' and pause while the list is filtered (3) Double-click the '''security.ssl3.dhe_rsa_aes_128_sha''' preference to switch it from true to false (disable Firefox from using this cipher) (4) Double-click the '''security.ssl3.dhe_rsa_aes_256_sha''' preference to switch it from true to false (disable Firefox from using this cipher) Then try to connect again. Any improvement? Note: I don't know the significance of having a VPN in the mix, but if the problem is between Firefox and the router, this is the best thing to try.