could not load type 'Microsoft.Xna.Framework.Color' from assembly 'System.Windows,'

Jun 24, 2013 at 2:19 PM
VS2012
SL5
XNA4.0
BabylonToolkit 1.04

where i run the code ' ObjImporter importer = new ObjImporter(SynchronizationContext.Current);'
it meets the problem!
anyone meets it?
please help