Standing on soul sand with any boots equipped as Demon results Internal Server Error.

I'd recommend also reporting that to the datapack author, seems more like they're thing.

Yeah, I'm not sure what that datapack or add-on even does. So I can't really help you here, sorry. Please report it to the datapack or add-on dev and tell them, that if they figure that the bug is on the side of Origins and not their add-on, they can feel free to report back here with more information. Thanks!
Closing this issue until then.