"Widget Error:Cannot read property 'text' of null" when adding or modifying views on a specific form.

 

Symptoms

When trying to add or change a rule on our form in the K2 designer, there is an error message in the subject line which prevents the user from making changes.
 

Diagnoses

A faulty SmartObject was being used within the form.
 

Resolution

Removing said SmartObject resolved the issue.