Fails to Compile C# project due to primary reference

Question

I'm trying to compile the project with targeted framework as ".NETFramework 4.0". But I get the following warning:

The primary reference "XXX" could not be resolved because it has an indirect dependency on the framework assembly "System.Runtime.Serialization, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" which could not be resolved in the currently targeted framework. ".NETFramework,Version=v4.0". To resolve this problem, either remove the reference "Fdi" or retarget your application to a framework version which contains "System.Runtime.Serialization, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089".

Lacey Lacey · Accepted Answer · 2012-09-26T13:13:58

I found an earlier (but similar) problem: Visual Studio 2010: Reference Assemblies Targeting Higher Framework Version

Johannes Rudolph found this answer on MSDN's forums ( http://social.msdn.microsoft.com/Forums/en-US/msbuild/thread/dfadfb34-5328-4c53-8274-931c6ae00836 ):

However, there're 2 workarounds.

Option 1:

Step1: Unload the referencing project targeting .NET 2.0

Step2: Right click the unloaded project and select edit from context menu

Step3: Add <SpecificVersion>true</SpecificVersion> to the reference. Below is a sample from my repro solution:

<ProjectReference Include="..\HighFX\HighFX.csproj">
<Project>{8DD71CAF-BEF7-40ED-9DD0-25033CD8009D}</Project>
<Name>HighFX</Name>
<SpecificVersion>true</SpecificVersion>
</ProjectReference>

Step4: Reload the project. Now your should be able to build within the Visual Studio 2010, there could still be a warning as below, but the build can be successful.

Warning 1 The project 'XXX' cannot be referenced. The referenced project is targeted to a higher framework version (3.5)

Option2:

Use the command line tool csc.exe to build each of your source file, which won't prevent the building.

Fails to Compile C# project due to primary reference

1 Answers