So I got on mumble today, and it looked completely normal. But when I went back to it later, the cat bar on the side was gone, and so was the toolbar at the top. So now it's just a window with an x in the top corner (no minimize button) and a list of the rooms in whatever server I'm in. How do I get it back?
That seems to be the Minimal mode of Mumble. To disable it, right click on a channel -> configure -> Minimal mode.
If the menu bar is still visible, click on configure -> settings -> User interface and activate the "default layout".