Symptoms

>K2 Blackpearl SmartForms]- Creating a SmartObject in the K2 Web designer vs. SmartObject tester tool
 

Diagnoses

When you create SMO in K2 Designer, it doesn't recognize if the primary key is Identity or not, the primary key will be checked as required by default which is not required because it is Identity.
 

Resolution

This issue has been logged as a bug, TFS Item has been added for this issue.

to avoid having this issue now, there are two ways:

1- Create your SMO using Smartobject tester tool.
2- when you create your SMO using K2 designer, make sure to uncheck "Required" on the primary key property.