Hello this is combination of issues, assembly version issue. or, because one of the other packages references Newton.JSON version directly with a wrong version. And the old DLL's are still creating conflict.

Step 1: IMHO, I would global search all your csproj files and your app.config files for Newton.JSON and closely examine the versions for mismatches

Step 2: Ensure you have Binding redirects like so (or just remove the old versions all together)

<configuration>
  <runtime>
    <assemblyBinding xmlns="urn:schemas-microsoft-com:asm.v1">     
      <dependentAssembly>
        <assemblyIdentity name="Newtonsoft.Json" publicKeyToken="30ad4fe6b2a6aeed" culture="neutral" />
        <!-- whatever is your current version that should replace the 13.00 below -->
        <bindingRedirect oldVersion="0.0.0.0-13.0.0.0" newVersion="13.0.0.0" />
      </dependentAssembly>
    </assemblyBinding>
    <loadFromRemoteSources enabled="true" />
  </runtime>

Step 3: Get rid old stale dll's

1. Delete the stale DLL's.
2. Then Shudown VS
3. Lastly delete the bin and delete you %temp% folder for stale obj folder

Now rebuild a clean version