Today the Game Maker 2023.8 release dropped. It includes some major changes to how asset IDs work, but it seems to only have broken one thing in this engine, luckily: things without a valid bodytype (e.g. the stage editor cursor when you preview basic terrain) would cause an invalid ID crash.

For new projects, I've uploaded a new version of the YYZ source which fixes this issue.

If you've got an existing project, edit bodytype_step_self to add a sprite_exists check in the BODYTYPE_SPRITE blocks like so:

I also fixed the typo in on-screen text that claims the Footpath editor uses X to paste new segments, it's actually C like everything else.

(Oh yeah, and I've switched over to major.minor.patch version numbering instead of the incremental single number, so the version number listed on the itch page matches the actual file you download - not sure why I went with that weird scheme before)