Nope, no problems...
Also, even though technically you don't have any errors in your eventing, I think you've still went about it in the wrong way. I think having a parallel event for checking whether you've completed the puzzle is a bad way to check, a common event played in the actual number box event when you enter in a number would probably be better and could result in less weird problems.
Also why did you use switches for each of the numbers? Seems kinda useless, you can simply use variables for changing the graphics too. And having a million parallel events for simply checking whether a number has been changed and changing the graphics is a bad idea as well, again, tie it to a variable, instead of a switch, you can cut out the parallel events. They're very, very costly and are probably causing the weird errors. Each of them run 60 times per second, and you have a lot of them...
Sorry for being such a downer. It really is a unique idea, and you have a great artstyle. But how you event is kinda bad. I think it's what's causing the problems.