Half of theme menu covered by rogue panel

I’m currently working on designing a new site, and so far things have been going fine. At least until today.

I am running 4.0 and using a theme I purchased. When I click on “Theme Options” in the dashboard, half of the options are covered by what acts like an image, but simply says “General Options” (it’s not clickable).

The rest of the WP dashboard tabs are fine, but on the theme tab I suddenly can’t see half the tabs, and the image (I call it an image, but it is really just a white square that covers the page) cuts off half the tabs and the dialogue on the right of the screen. When I click on the tabs that are there, they seem to work fine but there is no way to access the covered tabs.

I have no idea how this happened, and I wasn’t doing anything I haven’t done a thousand times before over the last 3 months I’ve been setting up the site. It happened after I went to the WP “Appearance” tab and went to “Customize.” I was playing around with adding a widget in the footer (which I have done many times before), and when I went back to the dashboard it was like this. I deleted the widget just to be sure, but no change.

Anyone have any idea? I also contacted the theme designer, but this seems more like a dashboard image.