I have found a rather hilariously dumb but serious bug that crashes the current version of the game.
The version I am using is the latest at V3.1(most recent release as of (11/2022).
My game itself is based off a working version of a Fire Red, so no issues there.
The bug occurs when you or the enemy uses Struggle as an attack, and then the opposing pokemon uses Conversion 2 in an attempt to convert to a type that resists Struggle, which itself being typeless, breaks the universe in-game. (in the same fashion as the Yugioh V. Darts "infinity +1" moment). LIke, LITERALLY BREAKS THE GAME, as in, when you encounter this sequence (you use Struggle, then use Conversion 2 on the mon that used Struggle) the entire game just stops working.
You can test this yourself if you want to test, and it will allow you to load a savestate prior to the bug and freeze or load a savefile prior. However, upon that battle move sequence, the game freezes and stops functioning. You may never encounter this in your runs through the game, but many well-known Poketubers end up relying on Struggle in their content for certain videos. If not fixed it remains a bug that can and will completely crash your game, so be aware of it.
SMH I just started my first randomizer nuzzlocke of this hack and 10sec in my 3 starters end up making a trio that breaks the game, how am I THAT UNLUCKY??