Start at 1:07:45

https://www.twitch.tv/videos/149235127

You can see there's no text when I go to select a stage. I can start the stage, and then there's no music. I save and exit a few times, and then decide to just play the stage out and see if it fixes afterwards. So at 1:11:15, I just enter it again with the intention of just beating it without the music playing to see if the game fixes afterwards. Aaaand, something else entirely happens.

As soon as the stage starts, I get "stage cleared", and then I'm in a place with just the white spawn square. I have access to the overworld menu and can save... I'm just in a completely empty space. WTF happened?