The hack I'm having this issue with runs on SA-1, not sure what other information is needed, please help. Thank you!
Yoshi crashes the game upon touching the floor when Mario is not riding him
First things first, is it your hack, or one downloaded from the site? If it's your own hack, are there any other resources you've added to it besides SA-1?
The SA-1 pack on its own is considered pretty stable, and hacks on the site are generally bug-free, so if there's nothing else you've done with the hack it most likely is due to something in how you're playing it. It might be your choice of emulator (ZSNES, for instance, is well-known to have issues properly emulating SA-1) or something in your configuration with it (e.g. active cheats that aren't intended for the ROM).
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My own hack, I've added too many resources to count, but weirdly, after I ported everything to SA-1, Yoshi stopped working, in the manner I've described above.