I have been trying to create more difficult puzzles. My latest attempt has gone through 5 evolutions. The way I do it is to create the level, then solve it, then make it more difficult. Version 5 of this puzzle may be unsolvable, but it may just be that I am not a good enough solver to solve it. YASC's solver returns "Unsolved" after a couple of minutes. Takaken solver won't solve it because it has more than 64 boxes. I would like for the more adept solvers in this forum to look at the puzzle and try to solve it, and tell me if it is just more difficult, or if it is truly unsolvable.