App crashes after FirebaseAuth.DefaultInstance

I use FireBase authentication with a simple function that signs up a new user, it works great on the Unity Editor, but when I build it on my Android, it crashes the second it tries to read this line- FirebaseAuth auth = FirebaseAuth.DefaultInstance

This is the error I get before it crashes-
Java class com/google/firebase/auth/FirebaseAuthWebException not found. Please verify the AAR which contains the com/google/firebase/auth/FirebaseAuthWebException class is included in your app.

1. Why do I even get the Firebase-AuthWeb-Exception ?
2. Why can't it find that exception? (I tried to resolve jar files, and to re-import auth SDK but it didn't solve the issue

My app is simple- there's a SignUp button that calls this function-

Code (CSharp):

1. public void SignUp()
2. {
3.     FirebaseAuth auth = FirebaseAuth.DefaultInstance;  //The error is after this line
4.  
5.     auth.CreateUserWithEmailAndPasswordAsync(email.text, password.text).ContinueWith(task =>
6.     {
7.         if (task.IsCanceled)
8.         {
9.             Debug.LogError("CreateUserWithEmailAndPasswordAsync was canceled.");
10.             return;
11.         }
12.         if (task.IsFaulted)
13.         {
14.             Debug.LogError("CreateUserWithEmailAndPasswordAsync encountered an error: " + task.Exception);
15.             return;
16.         }
17.  
18.         // Firebase user has been created.
19.         Firebase.Auth.FirebaseUser newUser = task.Result;
20.  
21.  
22.         Debug.LogFormat("Firebase user created successfully: {0} ({1})",
23.             newUser.DisplayName, newUser.UserId);
24.        // SignInWithVerification();
25.     });
26.  
27.  
28. }

• Unity- 2108.2.12f1
• Build system- Gradle
• Firebase unity sdk 5.4.0 dotnet3

 

Hello,
I have same problem.
Could you find a solution?
thanks.

 

Fixed on version 5.4.2 of Firebase https://firebase.google.com/support/release-notes/unity?hl=es-419