Symptoms

If you click refresh on an input parameter mapping page of SmartObject event wizard Visual Studio tries to open all SmOs within the solution, even those which are in different projects within the same solution.
To reproduce this just open solution file which contain multiple projects with multiple SmartObjects each in Visual Studio 2010/2013, drop SmO Event on the canvas and click refresh on the parameter mapping page of the wizard.
 

Diagnoses

This is known issue with coldfix available via support request for K2 4.6.11:

TFS 592627 "K2 Blackpearl K2 for Visual Studio SmartObject References: K2 for Visual Studio crashes with large solutions when attempting to add or edit a reference"
 

Resolution

Please contact K2 support to request coldfix for this issue.