Symptoms

Customer created a data field to pass the "username" from the people picker control on the smartform since people pickerandltvalueandgt field in the item reference gives an empty value.

Customer had a smartform and used the name property of the people picker as the value to be passed to the data field. To verify that there is a value, they created a field in the custom list to save the copy of the value to a column value and it does show the correct user name.

However during the workflow steps, when trying to retrieve the username or userid from the data field, I get an error stating that the value is empty:

SmartObject property UserName is a required property for selected method GetUserDetails. Value must be set
 

Diagnoses

In the workflow launching rule on the submit button the SmartObject wasn't being passed into the Item Reference XML field in the input mappings section. Because of this, the item reference fields in the workflow had no SmO method definitions to pull data from, which is why there was an empty value.
 

Resolution

Dragged the associated SmO into the Item Reference XML field for the input mapping section.