No worries. These things happen. Definitely seen upgrades kill save files on web builds of things before. Just figured I aught to report it because I didn't know you'd uploaded a new version, so thought it might be another bug.
If all that's changed is a hash value somewhere, and the save file contents are still the same, I could probably hack the save file if I felt like putting in the effort and knew the hashes, etc. But it's probably quicker to just replay it later if I want to see what's next than to figure that out.
Still, overall a nice twist on the sliding maze puzzle game genre.