Login Error: There is an error in logging you into this application. Please try again later

Question

I am getting this error. When I try to sign in with facebook to my app. When I first time authentication it will correctly working. After I unistalled my application and now trying to sign in with Facebook on that I am getting this error.

Another Issue : After authenticate in device1 and try to login with facebook on device2 also same error is getting.

Solution I Found : when I remove App authentication from Facebook App Settings it is working in above scenario's but this is not an good solution how we can tell to users to do this action?

btnFbLogin.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                if(accessToken != null) {
                    boolean expires = accessToken.isExpired();
                    if(!expires) {
                        performFbLoginOrSignUp(accessToken);
                    }
                } else {
                    LoginButton loginButton = (LoginButton) findViewById(R.id.login_button);
                    callbackManager = CallbackManager.Factory.create();

                    if (loginButton != null) {
                        loginButton.setReadPermissions("public_profile", "email", "user_friends");

                        if (CommonUtil.isConnectingToInternet(LoginActivity.this)) {
                            loginButton.performClick();

                            loginButton.setPressed(true);

                            loginButton.invalidate();

                            loginButton.registerCallback(callbackManager, mCallBack);

                            loginButton.setPressed(false);

                            loginButton.invalidate();
                        } 
                    }
                }
            }
        });

In Facebook example also having an issue : GitHub link of Facebook example

Steps to reproduce :

1. Launch the app Login with Facebook Authenticate FB profile.

2. Un_install the app and install again.

3. Now try to Login with Facebook.

4. The above error will occur. because we already authenticated so need to access fb profile. but here we facing the issue.
5. Here already authenticated page is not showing.
6. I am using Native FB app with the device Xiaomi Redmi Note 3

Answer 1

The error occurs because of invalid hash key.

We can create Hash key using the below command and update the same here under Settings-> Basic -> Android HashKeys

keytool -exportcert -alias ADD_RELEASE_KEY_ALIASE_HERE -keystore ADD_UR_KEYSTORE_PATH_HERE | openssl sha1 -binary | openssl base64

You can find the Relase Key Alias of your keystore using the below command if needed:

keytool -list -keystore ADD_UR_KEYSTORE_PATH_HERE

I have also experience an issue like by using the above HashKey the login works fine if I install the release APK directly to the device, But when I upload the APK to Play Store and install app from store then it shows the same Login failed error. The fix for this is as follows:

1. Go to Release Management here
2. Select Release Management
 -> App Signing
3. You can see SHA1 key in hex format App signing certificate.

4. Copy the SHA1 in hex format and convert it in to base64 format, you can use this link do that without the SHA1: part of the hex.

5. Go to Facebook developer console and add the key(after convert to base 64) in the settings —> basic –> key hashes.