Both the Motion & Mode Lighting and the Room Lights apps allow the user to create a rule that depends on a button press, but does not include the specific button. Example from Room Lights:
Within Motion & Mode Lighting, this situation causes the app to fail with the error:
java.lang.NullPointerException: Cannot get property 'value' on null object
Suggested fix: validate the rule construction within the GUI and require button[s] to be designated whenever a button device is used in a rule before saving the rule
