Peculiar.. for that reason does that mean you cant see your own post even, this one? I guess you can see and reply to the messages waiting notification even if you cant navigate to the thread they are in.

If I had to guess, I'd say you have a plugin messing with the site thats not working properly. Maybe an adblocker or a javascript suppression type of thing.

Switching browsers to an alternative one is an easy first thing to try, without digging too much into settings.