Not being able to save a blank puzzle after I cleared it
On today's 12x12, I spent a while working on the puzzle before realizing something was wrong. I had saved it multiple times before. Then I reloaded the puzzle and the previous saved numbers were still there. I tried clearing it again and saving that, which didn't work.
Granted, there is certainly a reason for not saving a blank puzzle
But still, if it was wrong, I would not like to have that wrongness saved