I've managed to convert Bob. The issue was that his History field was empty causing it throw an exception. I've made the Bio converting more lenient to fix this issue. I've tested the JSON export and it seems to be working as intended in FoundryVTT. I'll include the fix in version 1.1.4.
In the meantime, you can download the JSON for Bob here: https://pastebin.com/qjbY2SB
I'll try to fix the import error soon as well, I think I might have enough info with just the JSON and the stack trace you provided, but if you do have the XFDF, that's welcome too.