Cannot read property 'settings' of undefined

[lcichanowicz]

Reported here:
https://our.umbraco.com/packages/backoffice-extensions/umbraco-forms-on-perplex-steroids/feedback-bugs/91814-cannot-read-property-settings-of-undefined

I have blank install of Umbraco 7.10.3 and 7.10.4 I have Forms installed, lastest version. When I create a form and edit properties all works fine. I install Perplex and now when I try to edit existing properties on a form nothing happens. Looking at console, I get the following JavaScript error:

[PerplexDaniel]

Can you confirm the fix I described here works? That is, since we remove certain field types from showing up at all (like Short Answer), this causes issues on forms that were already configured to use those removed fields.

As a more permanent fix I would have to look into another implementation for hiding the field types, or simply not hide the built-in fields by default.