When a recipe file is coded incorrectly and added to a data pack, reloading the pack/world does not show any errors in logs, keeps the data pack loaded, but disables everything in it.

See in the data pack.zip data/minecraft/recipes/oak_sapling.json

remove oak_sapling.json and the data pack works fine. Add it back in (because it's coded incorrectly) and it breaks.

Picture shows console logs before adding the recipe and after adding the recipe. No errors detected.