It doesn't appear to be tileset related (if such a thing were possible). The only other thing I could think of is it's related to the equipment. I removed each piece, one at a time, to see if would prevent the bug -- but it didn't. I don't know what else to try.
I know you're busy with Din's Legacy, so I don't expect you to have much time for this. I could archive the save file, if you want to look at it. If not, I understand.