我无法使用 Firebase 身份验证使用电子邮件和密码登录

Question

I am facing problem, When I try to login with email/password via Firebase Authentication. I have already enable the email/password in SIGN-IN-METHOD tab. But whenever I signup in the same app then it allow me and record inserted in Firebase console user list, but when I try to login with the registered email & password I can't move forward, and the exception message is:

The password is invalid or the user does not have a password.

For Login, my code is :

FirebaseAuth auth=FirebaseAuth.getInstance();

auth.signInWithEmailAndPassword(email, password)
                        .addOnCompleteListener(LoginActivity.this, new OnCompleteListener<AuthResult>() {
                            @Override
                            public void onComplete(@NonNull Task<AuthResult> task) {
                                pb.dismiss();
                                if (task.isSuccessful()) {
                                    // Sign in success, update UI with the signed-in user's information
                                    Intent intent = new Intent(LoginActivity.this, DrawerActivity.class);
                                    startActivity(intent);
                                    finish();
                                } else {
                                    // If sign in fails, display a message to the user.
                                    //   Log.w("Tag", "Tag signInWithEmail:failure", task.getException());
                                    Log.i("Tags", "Tags signInWithEmail:failure" + task.getException());
                                    Toast.makeText(LoginActivity.this, "Authentication failed.",
                                            Toast.LENGTH_SHORT).show();

                                }


                            }
                        });

Answer 1

This may be when for example user SomeUser registered with email some_user@gmail.com and any password. Then he signed in with google account of the same email and then tries to log in again using email of his google account. In this case google removes password after user links his firebase account to google account. Here are some details