VisualStudio bug?

Question

In VS 2010 created a new WinForm project. Added a new UserControl WPF.

2 compile-time errors appeared:

Error 1 The type \'Sys

Answer 1

In my case "System.Xaml" was added to the project automatically but giving the same type of error:

The type name 'IComponentConnector' could not be found in the namespace 'System.Windows.Markup'. This type has been forwarded to assembly 'System.Xaml, Version=4.0.0.0, Culture=neutral,.... .' Consider adding a reference to that assembly.

I've solved the problem by, just deleting the "System.Xaml" from References and again adding "System.Xaml, Version=4.0.0.0" from Framework.