MS Blend preview for silverlight 5 - Designer view Catastrophic failure by Mariam Kharebava

Hello, i have strange problem with blend for silverlight 5. I create new blank project , every time I try to add control (button, or textbox or something else, that has Content property), I' getting that error exception:

Stacktrace:Empty
"Exception: Catastrophic failure (Exception from HRESULT: 0x8000FFFF (E_UNEXPECTED))
at MS.Internal.XcpImports.CheckHResult(UInt32 hr)
at MS.Internal.XcpImports.FrameworkElement_MeasureOverride(FrameworkElement element, Size availableSize)
at System.Windows.FrameworkElement.MeasureOverride(Size availableSize)
at System.Windows.FrameworkElement.MeasureOverride(IntPtr nativeTarget, Single inWidth, Single inHeight, Single& outWidth, Single& outHeight)"

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The strange thing is , that if i leave control Content property empty "" - error disappears.

here is list of related software installed on my computer:

VS 2012 premium
MS blend preview for silverlight 5 version 4.1.20402.0
Silverlight 5 Toolkit - December 2011
Silverlight Developer x64
Silverlight 5
OS is Windows 7 x64 enterprise