WTF is up with my Photoshop?

Okay, so this has happened to me before but it's always fixed itself, which was great seeing how I don't know how it happens in the first place... Anyway, I've got this dotted line around the edge of my canvas and a little gray box in the corner as well. I know I've seen this question asked before but I don't remember how to fix it and I can't find the old post. Sorry. >.< Anyway, here's a cap of what happened.



If anyone could help I'll love you forever, LOL.