JsonConvert Not working in Newtonsoft.Json Asp.net MVC C#

Question

I'm using Newtonsoft.Json.JsonConvert but the error is as follows:

The type 'JsonConvert' exists in both 'Newtonsoft.Json, Version=9.0.0.0, Culture=neutral, PublicKeyToken=30ad4fe6b2a6aeed' and 'Newtonsoft.Json, Version=12.0.0.0, Culture=neutral, PublicKeyToken=30ad4fe6b2a6aeed'

Image of the error given

Here are the things I did:

1. I have built the project Build -> Clean then Build -> Rebuild
2. I right-clicked on the project and Unloaded Project and then Reload Project
3. I once deleted and reinstalled Newtonsoft.Json

I have done all the above but the problem has not been solved what should be done? I use .net 4.6.1

in web.config (runtime tag)

<runtime>
    <assemblyBinding xmlns="urn:schemas-microsoft-com:asm.v1">
      <dependentAssembly>
        <assemblyIdentity name="Antlr3.Runtime" publicKeyToken="eb42632606e9261f"/>
        <bindingRedirect oldVersion="0.0.0.0-3.5.0.2" newVersion="3.5.0.2"/>
      </dependentAssembly>
      <dependentAssembly>
        <assemblyIdentity name="System.Web.Optimization" publicKeyToken="31bf3856ad364e35"/>
        <bindingRedirect oldVersion="0.0.0.0-1.1.0.0" newVersion="1.1.0.0"/>
      </dependentAssembly>
      <dependentAssembly>
        <assemblyIdentity name="WebGrease" publicKeyToken="31bf3856ad364e35"/>
        <bindingRedirect oldVersion="0.0.0.0-1.6.5135.21930" newVersion="1.6.5135.21930"/>
      </dependentAssembly>
      <dependentAssembly>
        <assemblyIdentity name="Newtonsoft.Json" publicKeyToken="30ad4fe6b2a6aeed"/>
        <bindingRedirect oldVersion="0.0.0.0-12.0.0.0" newVersion="12.0.0.0"/>
      </dependentAssembly>
      <dependentAssembly>
        <assemblyIdentity name="System.Web.Helpers" publicKeyToken="31bf3856ad364e35"/>
        <bindingRedirect oldVersion="0.0.0.0-3.0.0.0" newVersion="3.0.0.0"/>
      </dependentAssembly>
      <dependentAssembly>
        <assemblyIdentity name="System.Web.Mvc" publicKeyToken="31bf3856ad364e35"/>
        <bindingRedirect oldVersion="0.0.0.0-5.2.4.0" newVersion="5.2.4.0"/>
      </dependentAssembly>
      <dependentAssembly>
        <assemblyIdentity name="System.Web.WebPages" publicKeyToken="31bf3856ad364e35"/>
        <bindingRedirect oldVersion="0.0.0.0-3.0.0.0" newVersion="3.0.0.0"/>
      </dependentAssembly>
    </assemblyBinding>
  </runtime>

Answer 1

This happens because your project itself contain a Newtonsoft JSON library with version A and one of the other project it reference also contains Newtonsoft JSON library version B.

Try referencing a single version to both the projects.

You can try

1. Remove the older one, preferably (from one of the project)
2. Clean and rebuilt entire solution
3. Resolve the new references