I'm no longer getting notifications of blocked pop-ups or redirects, and am no longer getting the naggiest notification of the cert problem, though the connection is still not secure. This is out of my wheelhouse, so take what I say next with a grain of salt: I'm guessing you were (quite understandably) not putting out the cash for the EV SLL cert, and it never nagged anyone about it because as a simple forum the site wasn't asking anyone's system for any information that would require an encryption. Then the redirects and pop-ups tried asking for things they shouldn't have been, leading to warnings, and now that they're gone we're back to normal.