With judicial and excessive use of the ERASER, of course! Heh, you must have gone over the six hour memory limit. Sucks, right? Good luck!

I crie ever tiem

Oh, you think this is a problem? :P I lost my redo-function at about 1/3 of my progress once. Then finished the painting. AND THEN I DELETED ALL OF MY PROGRESS PAST THAT POINT BECAUSE OF A MISTAKE I REALLY COULDN`T FORSEE! (Namely, I was watching the whole playback and then went back to the painting)

That evening I was... reading a good book... And then I listened to the Tallon Overworld theme (because it was a Matroid fanart). I redrew the whole thing and uploaded it two days later. I could really go into a drawing frenzy back then :P

Oh noez D: Maybe um hm... save the picture that you have and trace from it? Then continue. OR just keep going :D

Here's the best advise I can give you:
It's too late now, just to be clear. Try not to move layers around, because that will trigger the glitch. Remember to do this every time you do a big painting: ALWAYS, go to "Make a copy" after doing something else like going to the gallery or wanting to play a game so you have two drawings.
Trust me, it's a life saver. When two layers of 30 ponies disappeared, I laughed at the glitch because I had two, then continued painting.
Please, the last thing I want to see is "I quit the collab". Take a deep breath, clear your mind, and focus on the OCs that you'll draw next.

Run in circles! D:
At least your top screen work :s & I just wish you the best of luck.

lik if u cry evry tim

^ i likd dis cuz i cry evry tiem I wish the update would be approved sooner so we don't have to deal with this. :P

This happened to me on the collab I'm working on. VERY annoying! DX

oh god!