Sooooooooo...... it was probably something that I did and am wondering if it can be undone?
I installed one theme and didn't care for it and then installed another theme on top of it. In so doing, the entire forum has disappeared.
I get this message stating be careful here your information isn't encrypted and then below that something about managing permissions.
Plus, when I copy the link of my forum to opera or even IE, I'm being told its an error500.
Try to add to your url ?theme=1
That will attempt to use the default theme.
Or if that doesn't work, look in smf_settings table in your database and set theme_default = 1.