IMPORTANT UPDATE: The project is almost ready! Just some final checks and it should exported and shipped off shortly! Sadly, I couldn't get the save file feature working, although the save and load feature is still there.
So the error seems to boil down to one thing The program uses an array to store the current canvas data, and it grabs from a .txt file for saving a loading. But the arrays show up as nil, because there's something wrong with the file.