Symptoms

We added two additional columns to the SQL table R that is surfaced through a smartobject. These two columns were ID's from a separate table F, acting as Foreign Keys. SQL Service instance and also smartobjects were all refreshed and used same GUIDs. When we attempt to edit a view that has the F smartobject as a data source we get the error:

"Parameter value can not be null. Parameter Name: s"

If we edit a form containing this view we see a spinner constanly attempting to load and this does not go away until we refresh the designer page.

 

Diagnoses

A smartobject association has been set for the ID from F to the 3 corresponding columns in R that used this ID. We tested regenerating the smartobject again and refreshing the service instance. The smartobjects themselves perform as intended in the SmartObject Service Tester tool and also when we run the view in design time or runtime. The issue spinning issue only appears upon editing the form on the designer site. Form will function properly on run time as well as design time URL.

Looking in Fiddler we saw that the form spinning was getting stuck on the AJAX call to get the properties of the F SmartObject. This led us to believe that the properties on this smartobject were still out of sync with that of the actual data source, the SQL Table.

We had previously only tried regenerating the smartobjects, never recreating them entirely.
 

Resolution

After deleting and then recreating the smartobject with the same GUID used before we then saw the views were editable and so were the form. We no longer had the error on views and the constant spinner on the form. The SmartObject associations also had to be recreated in designer because we deleted this smartobject, those were linked up just like before. Most likely explanation is that the regeneration of the smartobject did not pick up all of the new columns that we had added to the SQL table. Recreation made these new columns pull in and the checking of the properties now validated properly on the view.