Getting Uncaught Error cannot create property ‘validation’ on string ‘string’ when I have fields property as well as a validation property. If I get rid of either of those...

Getting Uncaught Error cannot create property ‘validation’ on string ‘string’ when I have fields property as well as a validation property. If I get rid of either of those it works, but together it’s causing problems. Any idea what gives?

Could be some bug in the schema validation - I'll see if I can reproduce.
You can't combine

type: 'string'

with

fields

, though - are you looking for

type: 'object'

?