Is there a sample project or a code fragment where the issue can be reproduced?

I was afraid you were going to ask. I'll see if I can put one together.

Here is a gist with a sample program: https://gist.github.com/pulse-matt/7796669

I'm using 2.5.0 of SharpDX "DirectX11_1-Signed-net40"

The above Gist runs OK in Windows 8. But crashes in Windows 8.1.

TextRenderer inherits from ICallbackBase which inherits from Dispose(). It is stated in the documentation that the Shadow object (stored in the property of ICallbackBase) should be disposed when disposing a ICallbackBase object, but in your implementation, you are not implementing correctly the Shadow property and not releasing it. You get a NullPointerException because of the Shadow is not stored and return null in any case. All samples in SharpDX that are using Direct2D callbacks are using CallbackBase.

Simply inherit from CallbackBase and TextRenderer and this should fix your issue.

That fixed it. Thanks.