the type from assembly is built with an older version of blend sdk and is not supported in a windows presentation foundation 4 project

Question

I created a WPF project in VS 2013. After upgrading to VS 2015, this error showed in the designer on types derived from the Blend SDK:

the type from a

Answer 1

None of the other answers here worked for me. What finally solved it was deleting the .NET v4.0 version of the file in the SDK folder:

C:\Program Files (x86)\Microsoft SDKs\Expression\Blend\.NETFramework\v4.0\Libraries\

I am referencing the v4.5 file via NuGet, but it seems that the designer was finding the file in the above folder. The v4.0 file was not registered in the GAC.