Interesting, what was the process you did, you started a game with the mod, removed it and loaded the save, then added it back in?
Thanks for reporting! I'll try to get this fixed shortly (might be a day or two). I don't know if there might be other side effects though... Playing without the mod for awhile and then adding it again might cause other hidden issues.
EDIT:
So I think if you unload it, and reload the mod, you have essentially wiped all the storage data (with how my init function works). I suspect it may force you to respawn as a new player and other things will likely break too.
I can definitely fix the error, because the crash is simple, but it's not simple to allow players to remove the mod and re-add it and expect the rest of the mod to keep working...
Sorry! If you want to try and recover your save, if you have old saves where the mod was active, and a newer save, the one that is causing the error, please dm me on discord and I can try to help you fix the save file if I can.
If you haven't made much progress, I'd recommend starting a new save though.