Firebase Database in Unity with REST API - unity3d

Question

I am trying to create a connection to the Firebase Realtime Database by following this tutorial: https://medium.com/#rotolonico/firebase-database-in-unity-with-rest-api-42f2cf6a2bbf to understand how it works and modify as I go. However, I am getting the following errors (these are just some of the errors):
Assembly DLL name is reserved for internal use: Assets/UnityEngine.dll (did files generated by a build accidentally end up in your Assets/ folder?)
C:\Program files\2019.4.20f1\Editor\Data\Resources\PackageManager\BuiltInPackages\com.unity.ugui\Runtime\UI\Core\FontData.cs(135,16): error CS0433: The type 'TextAnchor' exists in both 'UnityEngine.TextRenderingModule, Version=0.0.0.0, Culture=neutral, PublicKeyToken=null' and 'UnityEngine, Version=0.0.0.0, Culture=neutral, PublicKeyToken=null'`
C:\Program Files\2019.4.20f1\Editor\Data\Resources\PackageManager\BuiltInPackages\com.unity.ugui\Runtime\UI\Core\InputField.cs(241,10): error CS0433: The type 'SerializeField' exists in both 'UnityEngine.CoreModule, Version=0.0.0.0, Culture=neutral, PublicKeyToken=null' and 'UnityEngine, Version=0.0.0.0, Culture=neutral, PublicKeyToken=null'
These errors are populating when I did the following steps:
Navigate to the Build Files (DLL) folder.
Open CommonData.csproj in your favorite text editor.
Change the UnityInstallFolder value on line 6 to point to your Unity installation directory
On OSX this is likely /Applications/Unity/Editor
On Windows this is likely C:\Program Files (x86)\Unity\Editor
Double click FullSerializer.sln to open up the solution
Run a build-all (F6 in visual studio). Alternatively, you can right-click any of the three projects to build only one of them.
FullSerializer - NoUnity builds Full Serializer so that you can use it outside of Unity.
FullSerializer - Unity builds Full Serializer to a DLL
FullSerializer - Unity - WinRT builds Full Serializer with WinRT APIs (if you're targeting the Windows Store or the Windows Phone export platforms)
You will find the DLLs inside of the Build folder. Please add them to your Unity project's Asset folder.
Here is the path where unity is installed:
C:\Program Files\2019.4.20f1\Editor
I opened the FullSerializer.sln, and build one of the three projects, and so on.
I am not sure what I am doing wrong. Any help would be appreciated.

Answer 1

I was able to determine the issue. It appears that although the instruction suggests adding the source folder in the assets folder of the Unity Project, I remove it from there and put it in the same level as the assets folder. That resolved the issue. Hope this helps anyone else who has encountered this issue.