Symptoms

Widget Error on Rule Configure
 

Diagnoses

process:
Create new view generated from smartobject.
Skip to rules and edit the Save Button Clicked rule that was generated automatically.
Click "configure" and error message appears:
"Widget Error:The stylesheet does not contain a document element. The stylesheet may be empty, or it may not be a well-formed XML document."
I am unable to configure any rules on this new view or any for this project.

 

Resolution

Clearing cache and rebooting the system cleared the error.