How to solve System.Runtime.CompilerServices.Unsafe FileNotFoundException Google Protobuf? (Using C++ and C#) In Unity

After having changed my C++ code through my previous question, I found myself unable to display the data within Unity. It has a Debug.Log function which should display the 'array' I sent through from C#. Now this issue had evolved into a FileNotFoundException, tying into the currently asked question.

The error is as follows:

FileNotFoundException: Could not load file or assembly 'System.Runtime.CompilerServices.Unsafe, Version=4.0.4.1, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a' or one of its dependencies.
Google.Protobuf.CodedInputStream.ReadFloat () (at <817bcbeeba124ec59e5347ee91ea8025>:0)
Sphere.Sphere+Types+Position.MergeFrom (Google.Protobuf.CodedInputStream input) (at Assets/Scripts/Test/Sphere/Sphere.cs:385)
Google.Protobuf.ParsingPrimitivesMessages.ReadRawMessage (Google.Protobuf.ParseContext& ctx, Google.Protobuf.IMessage message) (at <817bcbeeba124ec59e5347ee91ea8025>:0)
Google.Protobuf.ParsingPrimitivesMessages.ReadMessage (Google.Protobuf.ParseContext& ctx, Google.Protobuf.IMessage message) (at <817bcbeeba124ec59e5347ee91ea8025>:0)
Google.Protobuf.CodedInputStream.ReadMessage (Google.Protobuf.IMessage builder) (at <817bcbeeba124ec59e5347ee91ea8025>:0)
Sphere.Sphere.MergeFrom (Google.Protobuf.CodedInputStream input) (at Assets/Scripts/Test/Sphere/Sphere.cs:199)
Google.Protobuf.ParsingPrimitivesMessages.ReadRawMessage (Google.Protobuf.ParseContext& ctx, Google.Protobuf.IMessage message) (at <817bcbeeba124ec59e5347ee91ea8025>:0)
Google.Protobuf.ParsingPrimitivesMessages.ReadMessage (Google.Protobuf.ParseContext& ctx, Google.Protobuf.IMessage message) (at <817bcbeeba124ec59e5347ee91ea8025>:0)
Google.Protobuf.FieldCodec+<>c__DisplayClass32_0`1[T].<ForMessage>b__0 (Google.Protobuf.ParseContext& ctx) (at <817bcbeeba124ec59e5347ee91ea8025>:0)
Google.Protobuf.Collections.RepeatedField`1[T].AddEntriesFrom (Google.Protobuf.ParseContext& ctx, Google.Protobuf.FieldCodec`1[T] codec) (at <817bcbeeba124ec59e5347ee91ea8025>:0)
Google.Protobuf.Collections.RepeatedField`1[T].AddEntriesFrom (Google.Protobuf.CodedInputStream input, Google.Protobuf.FieldCodec`1[T] codec) (at <817bcbeeba124ec59e5347ee91ea8025>:0)
Sphere.Spheres.MergeFrom (Google.Protobuf.CodedInputStream input) (at Assets/Scripts/Test/Sphere/Sphere.cs:704)
Google.Protobuf.MessageExtensions.MergeFrom (Google.Protobuf.IMessage message, System.IO.Stream input, System.Boolean discardUnknownFields, Google.Protobuf.ExtensionRegistry registry) (at <817bcbeeba124ec59e5347ee91ea8025>:0)
Google.Protobuf.MessageParser`1[T].ParseFrom (System.IO.Stream input) (at <817bcbeeba124ec59e5347ee91ea8025>:0)
Sphere_receive.Start () (at Assets/Scripts/Test/Sphere/Sphere_receive.cs:22)

EDITED The corresponding Sphere.cs block appeared to be to big for the body in its entirety, if you want to look at it please ask.

Now my own C# implementation of the original idea looked something like this:

using System.Collections;
using System.IO;
using UnityEngine;
using Sphere;
using Google.Protobuf;
using System.Runtime.CompilerServices;


public class Sphere_receive : MonoBehaviour
{
    private GameObject blockObj1, blockObj2, blockObj3;    
    private Vector3 position1, scale1, position2, scale2, position3, scale3;
    private Spheres sphereCollection;
    private string String;
    
    // Start is called before the first frame update
    void Start()
    {

    using(var input = File.OpenRead("./Assets/Scripts/sphereData.dat"))
    {
        sphereCollection = Spheres.Parser.ParseFrom(input);
    }

 
    Debug.Log(sphereCollection.ToString());

    }

    // Update is called once per frame
    void Update()
    {
        
    }
}

I dont know exactly whether the fact my Debug.Log not showing could be related to the thrown error, or if my implementation is simply wrong.

Solution

Okay so, after some very painful experimentation what has appeared to be the proper solution for me here was the following:

I looked up System.Runtime.CompilerServices.Unsafe v4.5.3 on the NuGet Gallery and dowloaded the package. (Version 4.5.3 is also assembly version 4.0.4.1)
Changed the downloaded .nupkg to a .zip (Don't know if it's a relevant step or not though)
Extracted it and located the System.Runtime.CompilerServices.Unsafe.dll file within the lib/netstandard2.0 folder
Dragged this .dll into the project folder

Seems the solution appeared a lot more simplistic than I had originally foreseen.