Yesterday night I tried out someone's project in progress and played with the skins a little (using 410.975). This morning I started up BYOND and went to try a project I'm working on. When I went to run it, I got a message that the skin has been updated (even though the project doesn't even have a Hub entry) and I declined it, but the game still wants to use skins, which just gives me a blank screen. (Then I tried creating a map skin, but I didn't get that right either.)
Since then I've tried creating and deleting an interface file, doing a clean compile, and even rebooting the computer, but I'm still getting this small blank window instead of the old BYOND behavior. What do I have to do to trick BYOND into using backward-compatibility mode?