Hello Sir / Madam,
I'm very familiar on serializing and de-serializing with Newtonsoft Nuget v13.0.1
I can help you to make those issues fixed and make the project up and running.
I have been using ASP.Net MVC from 2012.
Please contact to me for further discussions.
Regard,
Lasantha
BSc.(Hons)(Comp. Sci.), ACS, MCP(MCTS, MCSE, Azure Arch. (Tech)), Dip SE