Symptoms
When a view parameter shares a name with a SmartObject property, the rule will not save.
Clicking the Finish button in the Rules Configuration and then editing the rule shows that the changes have not been committed.
Diagnoses
This is a known issue in Smartforms 1.0.7
Resolution
Rename the view parameter so it no longer shares a name with the SmartObject property. This is slated to be fixed in 4.6.10