Symptoms

When creating a Smartforms-integrated process in K2 for Visual Studio in 4.6.9, an "Object reference not set to the instance of an object" error appears after clicking next on the Item Reference Wizard screen, regardless if an item reference was being created or not.
 

Diagnoses

This was identified as a bug with Smartforms Integration in the K2 thick-client tools, as the process worked fine in previous versions of Smartforms.
 

Resolution

A fix is available to resolve the issue and the following bug has been logged for the behavior:

Bug 544856: SFBug - K2 Designer - An item with the same key has already been added error using Smartforms integration wizard

Please contact k2 Support if you are experiencing this behavior in order to get a copy of the fix for K2 4.6.9.