Symptoms

When Creating a sharepoint smartobject on particluar site returns the above error. from K2 App for SharePoint.

SQL Server Subquery returned more than 1 value. This is not permitted when the subquery follows =, !=, <, <= , >, >=

So can't create the smart object itself.
 

Diagnoses

Duplicate in ProcessSharePointSetting table.
 

Resolution

Duplicate added to tK2].2Integration].nProcessSharePointSetting] where ListID = 'a9ca8bc3-a798-475f-b246-253d0d051e9f'
Deleted the duplicate and it is fixed.