Q:

SharePoint WebPart RestAPI exception Could not load file or assembly

I made a SharePoint 2013 WebPart in VisualStudio 2017 and I build a RESTapi as a console application with this tutorial:
Calling a Web API From a .NET Client (C#)
In my WebPart I create an object from the Restapi class to use it.
RestAPI restApi = new RestAPI();

In the constructor from the RestAPI class i call the 
RunAsync().Wait();

In this method i'm calling an other method.
and now my Problem:
I need to get the authentication ticket so i'm using this method:
HttpContent content = new StringContent("username=" + lgname + ";password=" + pswd, System.Text.Encoding.UTF8, "application/x-www-form-urlencoded");
HttpResponseMessage response = await client.PostAsync($"/OTCS/cs.exe/api/v1/auth", content);
response.EnsureSuccessStatusCode();
var authResponse = await response.Content.ReadAsAsync<AuthResponse>();
return authResponse.Ticket;

as an console application this works fine.
this is the AuthResponse class:
[JsonObject]

public class AuthResponse
{
    [JsonProperty("Ticket")]
    public string Ticket { get; set; }
}

I got the classes to format the JSON with http://json2csharp.com/
but when I use this in a SharePoint Webpart I get the following exception:

{"Could not load file or assembly 'System.Net.Http.Formatting,
  Version=5.2.3.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35' or
  one of its dependencies. The system cannot find the file
  specified.":"System.Net.Http.Formatting, Version=5.2.3.0,
  Culture=neutral, PublicKeyToken=31bf3856ad364e35"}
  System.Exception {System.IO.FileNotFoundException}

in the .csproj file the following entry can be found:
<Reference Include="System.Net.Http.Formatting, Version=5.2.3.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35, processorArchitecture=MSIL">
      <HintPath>packages\Microsoft.AspNet.WebApi.Client.5.2.3\lib\net45\System.Net.Http.Formatting.dll</HintPath>
    </Reference>

the formatting.dll can be found in the path.
the problem is that System.Net.Http.Formatting could not be found.
the issue is in the await response.Content.ReadAsAsync<AuthResponse>()
i tried to use:
JsonConvert.DeserializeObject<AuthResponse>(jsonString);

but then i get nearly the same exception:

{"Could not load file or assembly 'Newtonsoft.Json, Version=10.0.0.0,
  Culture=neutral, PublicKeyToken=30ad4fe6b2a6aeed' or one of its
  dependencies. The system cannot find the file
  specified.":"Newtonsoft.Json, Version=10.0.0.0, Culture=neutral,
  PublicKeyToken=30ad4fe6b2a6aeed"} System.Exception
  {System.IO.FileNotFoundException}

.csproj entry:
<Reference Include="Newtonsoft.Json, Version=10.0.0.0, Culture=neutral, PublicKeyToken=30ad4fe6b2a6aeed, processorArchitecture=MSIL">
      <HintPath>packages\Newtonsoft.Json.10.0.2\lib\net45\Newtonsoft.Json.dll</HintPath>
    </Reference>

Newtonsoft.Json.dll is located in the HintPath
the app.config looks like this:
<?xml version="1.0" encoding="utf-8"?>
<configuration>
  <runtime>
    <assemblyBinding xmlns="urn:schemas-microsoft-com:asm.v1">
      <dependentAssembly>
        <assemblyIdentity name="Newtonsoft.Json" publicKeyToken="30ad4fe6b2a6aeed" culture="neutral" />
        <bindingRedirect oldVersion="0.0.0.0-10.0.0.0" newVersion="10.0.0.0" />
      </dependentAssembly>
    </assemblyBinding>
  </runtime>
</configuration>

all the references are up to date and working when i tested it as a console application.
I'm using .NET v4.5 in the programm and in the SharePoint Server.
when i not catch the exception then i get this:

An exception of type 'System.AggregateException' occurred in
  mscorlib.dll but was not handled in user code Additional information:
  One or more errors occurred. occurred

i tried to reinstall the references but that did not work
so how can i get the references to work in the SharePoint Webpart?
Thanks

A:

In your webpart solution there is a package, inside the package you need to put all the assemblies (in the Advanced tab) you are going to use to add them to full trust.

