Symptoms
When you Submit a form you may get an error that states "item SmartObject property ID is a required property for selected UpdateList. Value must be set.".
Diagnoses
This error may happen when you either do not supply a valid value for the input for the method you are trying to execute.
Resolution
Ensure that you are passing the correct values for the method, you can check what parameters are required by editing the SmartObject.
This error may also occur within the rule of a button when the input values on the control have been automapped. In this case please check you are inputting the correct values that are being passed by the controls as the automapping will typically map the actual control to the field, rather than the value inputted into the control.