Edited Issue: SetBinding exception in Silverlight [9295]

The code behind binding throws an exception in Silverlight:

Attempt by method 'SLLocalizeExtension.Extensions.LocExtension.SetBinding(System.Object, System.Object, Int32)' to access field 'System.Windows.DependencyProperty._propertyType' failed.

in LocExtension.cs line 730.

I am using windows8 and vs2012.

My code is

TextBlock tt = new TextBlock();
LocExtension lex = new LocExtension("SRCommon:SRCommon:Modul_XXX");
lex.SetBinding(tt, TextBlock.TextProperty);