Symptoms

In an appified list, we get an “Object Not Found” error.

This list is referenced from another list as data drop down items. The other list shows errors referencing the reference appified list mentioned above, errors of type 'The SmartObject or one of its components could not be resolved. Value Cannot be null. Parameter name: s.'

I used this list mid-February last time and it didn't show any errors. If we made any changes or if there is something we are missing, please help us with clarifications. But I don't remember making any changes in this reference list.

 

Diagnoses

It appeared that all SmartObject for this site collection disappeared. When executing these SmartObjects from SmartObject Administration, we received "Value cannot be null. Parameter name: S" error.
 

Resolution

We were able to resolve the issue by regenerating SmartObjects for those lists.
1.Navigate to K2 App on the list that is broken
2.Click the dropdown next to New menu, and select Generate SmartObjects
3.Click the check box for Allow this SmartObject to be used in Workflows for this List/Library
4.Click OK button.