Pixel Brush Suddenly Quit Working?

I was working on a project with one specifc pixel brush, and have been for about an hour now. Everything was fine, despite the fact that I have a mouse cursor to work with. The program crashed about twenty minutes ago, thought no big deal, loaded it right back up, sent the error report. Got back to work, literally switched out of the program to answer an email... Came back and the brush just suddenly doesn't work. I've adjusted evrything, still nothing, restarted the program, still nothing. 

It's recgonzing that I'm doing something because I can hit undo, obviously there isn't anything to undo really that I can see visually... But there's nothing there. I use a Wacom tablet and stylus on Windows 10. I literally have never had so many issues with Fresco since updating it yesterday to the latest version.