It was the first time I tried https for the site. Maybe it has been like this from the start, idk.
Just leave the s out, then, and connect to the site normally as Kajhera said. I don't think MinMax is set up for https in the first place, and hosts letting their security certificates lapse happens.
My browser doesn't even connect with http at the front end of the url. Just jumps straight in with www.
Everything connects with http by default. Your browser just doesn't show you that part at the start of the address because it's the same for each site. If you highlight your address bar and copy-paste it somewhere, you'll probably find the http is there at the start of the url.
Oh, hey, security thread! Anyone know if MMX was exposed to the Heartbleed error/bug?
No idea, I'm afraid. However, as I understand it, Heartbleed requires someone to actively try to leech data from a target, which gives us a kind of security in obscurity - MinMax is a small community, in the grand scheme of things. I wouldn't be too worried, partly because of that, partly because I doubt anyone has sensitive information stored on their account here. The big targets of Heartbleed-based security breaches are banks and similar, not hobby discussion forums.
Change your password just in case if you're worried, which is a good idea to do anyway once in a while, and make sure you aren't using your MinMax password for anything important (if you are, change those too, preferably to something other than what you change your MMX password to). If you haven't gotten an email from your bank on whether their services were compromised, call their customer service or a personal consultant if you get one and ask.