Symptoms

A couple of updates was made to two SQL tables that are connected to K2 as SmartObjects. I have refreshed the service instance, updated the tables through the 'generate SmartObjects' section, but now when I try to generate a view from this Smartobject, I get the "Value cannot be null.Parameter name: s" error message. This Smartobject executes successfully and returns data.
 

Diagnoses

This Smartobject had an association to another Smartobject which tables had been deleted and will not be used. Execution of this associated Smartobject also resulted in the "Value cannot be null.Parameter name: s" error.
 

Resolution

As this associated Smartobject will no longer be used, we removed this Smartobject association this allowed the generation of views on the Primary Smartobject.