(This article is currently in English and Japanese only)

If you see the error message "Unable to Authenticate " and "Failed to Log in" , please check the following four points:

1.You may not be able to sign in on devices that are not Play Protect certified.

If you are unable to sign in on a non-certified device, please consider using a Protect certified devices


Monster Hunter Now only supports devices that have been certified for Play Protect. For details, please refer to FAQ:Supported Devices.

2.Check your pop-up blocker settings:

We have confirmed that some pop-up blockers block the screen required for Google Login. Please exclude sites related to Google Login from your pop-up blocker settings, or temporarily stop the pop-up blocker settings, and then restart the application and try to log in again. Please contact the service provider of the pop-up blocker you are using for instructions on how to change your pop-up blocker settings or suspend the pop-up blocker.

3.Verify integrity on your Android device: 

If the issue persists, enable the Developer Options on your Android device and perform the "Verify Integrity". Please provide the screenshot of the generated screen via this Web Form for further debugging and troubleshooting.

Steps to enable Developer Options:

    1. Tap on Google Play Store.

    2. Tap on the profile icon at the top right corner.

    3. Tap on "Settings."

    4. Tap on "About" or "Device information."

    5. Tap the line that says "Play Store version" seven times. 

You will see a message saying, "You are now a developer!"

*Messages will vary depending on the model and OS version.

Steps to perform "Verify Integrity" from enabled Developer Options: 

  1. Launch Google Play Store again.
  2. Tap on the profile icon at the top right corner.
  3. Tap on "Settings."
  4. Tap on "General."
  5. Tap on "Developer options."
  6. Tap on "Play Integrity" settings and select "Verify Integrity" or “Check Integrity” (Text may vary depending on your device).

If you see an error message, including the word "Error," it indicates a security issue (such as the use of unauthorized tools or rooting) that prevents you from using the Monster Hunter Now app. If you don't have any related knowledge or recollection, please consult Google Play Support or provide a screenshot of this screen using this Web Form for further assistance.

4. There may be a temporary problem

In addition, you may receive error messages such as "Login failed" or "Authentication failed." if our servers are experiencing a temporary issue or your network connectivity is poor.

Please check your device's network connection and try logging in again after waiting for a while. If the issue persists, try restarting the Monster Hunter Now app.

If the problem still persists, clearing the app cache or reinstalling the app may help resolve the issue. If none of these steps resolve the issue, please contact us for further assistance.