Could not load file or assembly 'Newtonsoft.Json, Version
The reason might be mixed versions of newtonsoft in your project.
Make sure you either use the newtonsoft dll that already exists in your project
without adding new nuget package , or remove the old dll and nuget references
and then add a new one, you can look at packages.congif\app.config\web.config
or the references tab in your project to find out the issue better