I have a sample Avalon application downloaded from the net. When running the application I get the below error message:
Unknown build error, 'Value cannot be null.
Parameter name: target.' D:\WindowsVista\Samples\Valil.Chess.WinFX\Valil.Chess.WinFX\Chess3DPage.xaml Valil.Chess.WinFX
I am getting this error in the XAML files of only one project out of five projects in the solution and I am able to re-build the entire solution successfully.

Unknown Build Error
dee-u
Hi,
Thank you for the response.
Sorry for my delayed response. Yes, I did try rebuilding the entire solution. But still the same problem persists.
TIA.
bobsmith
Hi,
Can you provide me the location where you downloaded the application, the error could be due to various reasons, including wrong version of WPF installed.
Thanks
Sunil
Dave Kaplan
I think it's the same issue with incremental build mechanism. Mahalax, did you try to rebuild the entire solution