Robert,

>*******************************************************************FIX********************************************************************************
>Hello. I placed "Me._building.Cancel()" in the cancel event of the button. I didn't think I had to do this since Me._building is registered as the primary BO.
>
>Doesn't the form call the necessary events for the primary BO?
>

Yes, it should definitely call the primary business object for you automatically. I recommend open the MM .NET mmButtonCancel source code in your project, setting a breakpoint in the mmButtonCancel_Click() event handler to see what's happening.

Best Regards,