Thanks for so quick reply, but I think I mess the system up entirely. And also, I see to manage to do something like this in the first puzzle of the Tile Trial I made(!), but I only made it so that if one crystal can cover it, the other one can uncover it. Still, I will need to work the things out. Anyway, thanks for the help. I thought that I properly evented the "Restart" system but it fails... Think I'm gonna just force player to save before each puzzle and when asking him/her to restart they'll have to load the savefile. Such a fail...
Of course, I could post the project as it holds the puzzle, but currently I just don't want to do that as it would be a bit too much.
'Kay, enough talk.