Azure Active Directory Unity Authentication Error - unity3d

Question

I'm trying to implement Azure AD authentication into my Unity app. I have started with the code and documentation from here: https://learn.microsoft.com/en-us/azure/active-directory/develop/quickstart-v2-windows-desktop . Their Visual Studio example project works fine, however when I try to use this code within my Unity project it fails when trying to run it.
string[] scopes = new string[] { "user.read" };
public static string ClientId = {...} // my azure app id
private static string Tenant = {...} // my tenant id
private async void AsyncLoginButton()
{
AuthenticationResult authResult = null;
string authority = "https://login.microsoftonline.com/" + Tenant;
var app = new PublicClientApplication(ClientId, authority, TokenCacheHelper.GetUserCache());
{...}
try
{
authResult = await app.AcquireTokenAsync(scopes);
}
catch (MsalException msalex)
{
textContent.text = $"Error Acquiring Token:{msalex}";
Debug.Log(msalex);
}
{...}
}
with the following error - "Could not register the window class, win32 error 0":
After pressing OK on the above window it just gives a null reference at the line with AcquireTokenAsync.
NullReferenceException: Object reference not set to an instance of an object
Microsoft.Identity.Client.Platforms.net45.WebUI+<AcquireAuthorizationAsync>d__16.MoveNext () (at <a854dd38cefc420d850373110dec4a99>:0)
--- End of stack trace from previous location where exception was thrown ---
System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw () (at <ac823e2bb42b41bda67924a45a0173c3>:0)
System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess (System.Threading.Tasks.Task task) (at <ac823e2bb42b41bda67924a45a0173c3>:0)
System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification (System.Threading.Tasks.Task task) (at <ac823e2bb42b41bda67924a45a0173c3>:0)
System.Runtime.CompilerServices.TaskAwaiter.ValidateEnd (System.Threading.Tasks.Task task) (at <ac823e2bb42b41bda67924a45a0173c3>:0)
System.Runtime.CompilerServices.ConfiguredTaskAwaitable`1+ConfiguredTaskAwaiter[TResult].GetResult () (at <ac823e2bb42b41bda67924a45a0173c3>:0)
Microsoft.Identity.Client.Internal.Requests.InteractiveRequest+<AcquireAuthorizationAsync>d__10.MoveNext () (at <a854dd38cefc420d850373110dec4a99>:0)
--- End of stack trace from previous location where exception was thrown ---
System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw () (at <ac823e2bb42b41bda67924a45a0173c3>:0)
System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess (System.Threading.Tasks.Task task) (at <ac823e2bb42b41bda67924a45a0173c3>:0)
System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification (System.Threading.Tasks.Task task) (at <ac823e2bb42b41bda67924a45a0173c3>:0)
System.Runtime.CompilerServices.TaskAwaiter.ValidateEnd (System.Threading.Tasks.Task task) (at <ac823e2bb42b41bda67924a45a0173c3>:0)
System.Runtime.CompilerServices.ConfiguredTaskAwaitable+ConfiguredTaskAwaiter.GetResult () (at <ac823e2bb42b41bda67924a45a0173c3>:0)
Microsoft.Identity.Client.Internal.Requests.InteractiveRequest+<ExecuteAsync>d__9.MoveNext () (at <a854dd38cefc420d850373110dec4a99>:0)
--- End of stack trace from previous location where exception was thrown ---
System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw () (at <ac823e2bb42b41bda67924a45a0173c3>:0)
System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess (System.Threading.Tasks.Task task) (at <ac823e2bb42b41bda67924a45a0173c3>:0)
System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification (System.Threading.Tasks.Task task) (at <ac823e2bb42b41bda67924a45a0173c3>:0)
System.Runtime.CompilerServices.TaskAwaiter.ValidateEnd (System.Threading.Tasks.Task task) (at <ac823e2bb42b41bda67924a45a0173c3>:0)
System.Runtime.CompilerServices.ConfiguredTaskAwaitable`1+ConfiguredTaskAwaiter[TResult].GetResult () (at <ac823e2bb42b41bda67924a45a0173c3>:0)
Microsoft.Identity.Client.Internal.Requests.RequestBase+<RunAsync>d__16.MoveNext () (at <a854dd38cefc420d850373110dec4a99>:0)
--- End of stack trace from previous location where exception was thrown ---
System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw () (at <ac823e2bb42b41bda67924a45a0173c3>:0)
System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess (System.Threading.Tasks.Task task) (at <ac823e2bb42b41bda67924a45a0173c3>:0)
System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification (System.Threading.Tasks.Task task) (at <ac823e2bb42b41bda67924a45a0173c3>:0)
System.Runtime.CompilerServices.TaskAwaiter.ValidateEnd (System.Threading.Tasks.Task task) (at <ac823e2bb42b41bda67924a45a0173c3>:0)
System.Runtime.CompilerServices.ConfiguredTaskAwaitable`1+ConfiguredTaskAwaiter[TResult].GetResult () (at <ac823e2bb42b41bda67924a45a0173c3>:0)
Microsoft.Identity.Client.PublicClientApplication+<AcquireTokenForLoginHintCommonAsync>d__22.MoveNext () (at <a854dd38cefc420d850373110dec4a99>:0)
--- End of stack trace from previous location where exception was thrown ---
System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw () (at <ac823e2bb42b41bda67924a45a0173c3>:0)
System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess (System.Threading.Tasks.Task task) (at <ac823e2bb42b41bda67924a45a0173c3>:0)
System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification (System.Threading.Tasks.Task task) (at <ac823e2bb42b41bda67924a45a0173c3>:0)
System.Runtime.CompilerServices.TaskAwaiter.ValidateEnd (System.Threading.Tasks.Task task) (at <ac823e2bb42b41bda67924a45a0173c3>:0)
System.Runtime.CompilerServices.ConfiguredTaskAwaitable`1+ConfiguredTaskAwaiter[TResult].GetResult () (at <ac823e2bb42b41bda67924a45a0173c3>:0)
Microsoft.Identity.Client.PublicClientApplication+<AcquireTokenAsync>d__5.MoveNext () (at <a854dd38cefc420d850373110dec4a99>:0)
--- End of stack trace from previous location where exception was thrown ---
System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw () (at <ac823e2bb42b41bda67924a45a0173c3>:0)
System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess (System.Threading.Tasks.Task task) (at <ac823e2bb42b41bda67924a45a0173c3>:0)
System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification (System.Threading.Tasks.Task task) (at <ac823e2bb42b41bda67924a45a0173c3>:0)
System.Runtime.CompilerServices.TaskAwaiter.ValidateEnd (System.Threading.Tasks.Task task) (at <ac823e2bb42b41bda67924a45a0173c3>:0)
System.Runtime.CompilerServices.TaskAwaiter`1[TResult].GetResult () (at <ac823e2bb42b41bda67924a45a0173c3>:0)
ApplioMGE.Login+<AsyncLoginButton>d__37.MoveNext () (at Assets/Scripts/Transitional/Login.cs:136)
--- End of stack trace from previous location where exception was thrown ---
System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw () (at <ac823e2bb42b41bda67924a45a0173c3>:0)
System.Runtime.CompilerServices.AsyncMethodBuilderCore+<>c.<ThrowAsync>b__6_0 (System.Object state) (at <ac823e2bb42b41bda67924a45a0173c3>:0)
UnityEngine.UnitySynchronizationContext+WorkRequest.Invoke () (at C:/buildslave/unity/build/Runtime/Export/UnitySynchronizationContext.cs:111)
UnityEngine.UnitySynchronizationContext.Exec () (at C:/buildslave/unity/build/Runtime/Export/UnitySynchronizationContext.cs:72)
UnityEngine.UnitySynchronizationContext.ExecuteTasks () (at C:/buildslave/unity/build/Runtime/Export/UnitySynchronizationContext.cs:93)
I assume this happens when the code is trying to pop up the Microsoft Graph API window which asks for your credentials, but for some reason this doesn't work in Unity.
Any ideas?
Thank you.