"Value must validate against one of the provided schemas"

[eduo]

Hi.

I am trying to make a section of a form depend on a selected item in a popup. I must be doing something wrong since no matter what I try, I always get the error that the "Value must validate against one of the provided schemas".

This is the form: https://is.gd/yalBCt
I've simplified it enormously for the purpose of reporting it. The original form contains width indicators, format validations, etc.

At the moment one option in the "type of item" displays a small additional form and the other option shows nothing. No matter what either contains, the error appears.

Once fixed I'd like to set-up a default value for this pop-up, but nothing I've tried has worked (for a while I thought that was the issue, but no)