How to force WebAPI to use JSON.net 6.0.3 instead of 4.5?

Question

After adding WebAPI and register it in Global.asax.

We find our web app breaks at this line:

Line 17:             GlobalConfiguration.Configure(WebApiConfig.Register);

Error message:

Could not load file or assembly 'Newtonsoft.Json, Version=4.5.0.0, Culture=neutral, 
PublicKeyToken=30ad4fe6b2a6aeed' or one of its dependencies. 
The system cannot find the file specified.

After some checkup, I find we are using Json.net 6 in this MVC 5.1 application. Does it mean we have to downgrade to Json.net 4.5 for WebAPI to work?

---

In my .csproj file, there is only one entry:

<Reference Include="Newtonsoft.Json, Version=6.0.3.0, Culture=neutral, PublicKeyToken=30ad4fe6b2a6aeed, processorArchitecture=MSIL">
  <SpecificVersion>False</SpecificVersion>
  <HintPath>..\packages\Newtonsoft.Json.6.0.3\lib\net45\Newtonsoft.Json.dll</HintPath>
  <Private>False</Private>
</Reference>

When I look into my Json.NET in Manage NuGet Packages, it also says my Json.NET is version 6.0.3.

In addition, there is already the bindingRedirect statement in my web.config.

  <dependentAssembly>
    <assemblyIdentity name="Newtonsoft.Json" publicKeyToken="30ad4fe6b2a6aeed" culture="neutral" />
    <bindingRedirect oldVersion="0.0.0.0-6.0.0.0" newVersion="6.0.0.0" />
  </dependentAssembly>

But, if I look into the references of the web project inside visual studio. The path of Newtonsoft.Json points to C:\Program Files (x86)\Microsoft Visual Studio 12.0\Blend\Newtonsoft.Json.dll but Copy Local is false.

How can that be? How can we handle this conflict?

Baptist

Are you sure that code is correct and it shouldn't be WebApiConfig.Register(GlobalConfiguration.Configuration);? – Adrell

That register statement is from asp.net/web-api/overview/extensibility/…. Is it correct? – Baptist

Make that correction as DavidG suggested. Same error. – Baptist

Answer 1

You need to add a binding redirection in your web.config (possibly merge with your existing binding redirections):

<runtime>
  <assemblyBinding xmlns="urn:schemas-microsoft-com:asm.v1">
    <dependentAssembly>
      <assemblyIdentity name="Newtonsoft.Json" publicKeyToken="30ad4fe6b2a6aeed" culture="neutral" />
      <bindingRedirect oldVersion="0.0.0.0-6.0.0.0" newVersion="6.0.0.0" />
    </dependentAssembly>
  </assemblyBinding>
</runtime>

Pb

Pretty sure that is not the solution. 'cause this statement is there already. But thanks for the input. – Baptist

@Baptist That's wield because I had exactly the same issue (same exception on same line) a few days ago and it was the solution. – Pb

@Baptist Have you tried reinstalling the NuGet package and setting CopyLocal to true? It's true in my project. – Pb

@Baptist This actually worked for me, but be sure to put in 6.0.0.0 and not the exact version. – Remonstrate

This worked for me except for a minor tweak in that config: <bindingRedirect oldVersion="4.5.0.0" newVersion="6.0.0.0" /> – Leucas

Answer 2

The redirect did not work for me until I update the Web Api to a recent version:

PM> update-package Microsoft.AspNet.WebApi.Client -Version 4.0.30506
Updating 'Microsoft.AspNet.WebApi.Client' from version '4.0.20710.0' to '4.0.30506.0' in project 'TestProject.Api'.

---

  <dependentAssembly>
    <assemblyIdentity name="Newtonsoft.Json" publicKeyToken="30ad4fe6b2a6aeed" culture="neutral" />
    <bindingRedirect oldVersion="0.0.0.0-6.0.0.0" newVersion="6.0.0.0" />
  </dependentAssembly>

Fargone

Answer 3

Okay, here is my fix.

Well one thing I don't know is how the Json.net reference points to the dll in the Blend folder in the first place.

I tried to re-NuGet but found it rather inconvenient because WebApi and WebGrease are all dependent on it.

So I just went ahead and deleted that reference. That of course breaks everything related.

When adding the reference back, I simply Add Reference by browsing to the dll under the /.package folder inside this project.

It works!

Pretty brutal? Just make sure we checked

• .csproj
• Web.Config
• the property in the Reference entry in VS

Dare to try after all bases are covered.

Baptist