System.Net.Http version conflict causing build warning

You can try the workaround mentioned in this Microsoft Connect bugreport.

Or you can try and add something like this to your Web.config:

  <runtime>
    <assemblyBinding xmlns="urn:schemas-microsoft-com:asm.v1">
      <dependentAssembly>
        <assemblyIdentity name="System.Net.Http" publicKeyToken="b03f5f7f11d50a3a" />
        <bindingRedirect oldVersion="0.0.0.0-4.0.0.0" newVersion="4.0.0.0" />
      </dependentAssembly>
    </assemblyBinding>
  </runtime>

Edit:

This is the workaround in the Connect Bug:

modify…….: <Reference Include=”System.Net.Http”>
to read ……: <Reference Include=”System.Net.Http, Version=4.0.0.0″>