Issue Summary

Preview for JSM form does not load in some cases and displays error "something went wrong, refresh the page and try again. If the error persists, contact support"

This is reproducible on Data Center: (no)

Steps to Reproduce

This bug occurs if the JSON for the form is in an incorrect state. Currently, it is observed for radio buttons. In some cases, if the form has a radio button field, the JSON form will have empty children added. Ideally, only cascading fields can have children and not radio buttons. This puts the JSON in an inconsistent state.

1. Create a new project form in Project Setting -> Forms
2. Add a Cascading Dropdown field
3. Add some parent and child options
4. Select the Cascading Dropdown field
5. Change the field type to Radio Buttons (or any other choice field types)
6. Click Preview

Expected Results

Preview should works correctly. In the JSON file for the form, the radio buttons should not have any children added.

Actual Results

Preview is broken. The JSON file for the form has children added for radio buttons.

Workaround

Delete the options in the form field and manually add them again. This will fix the issue.