How to fix Package file is invalid error on Google Play Store (Nothing else worked)

It is possible that the latest version of the Google Play Store app is the reason behind this error, probably because it was downloaded and installed improperly. Maybe a (stuck) background process interfered with installing the app, or the Internet connection is unstable.

In this case, you need to revert the Google Play Store app to the default version, by following the steps mentioned below:

1. Go to Settings and tap on Application Manager/Apps;
2. Tap on Google Play Store, and select Uninstall updates;
   

   
   
   

3. Tap on OK to confirm; 
4. Open the Google Play Store app.
   
   

The video guide below demonstrates how to uninstall updates:

Note: The video guide above was recorded on a Samsung Galaxy device, running on Android OS 8 - the steps described may slightly vary from one device to another.

If you can't fix this error, try wiping the cache partition through the recovery menu. The recovery menu is a secret menu with options that ensure that you can regain access to your device, and fix errors even if the operating system is inaccessible.

To access the recovery mode and wipe the cache partition, follow these steps: 

1. Power off the device. If you can't do that using the power button, just remove the battery and insert it after 10 seconds.
   
   
2. Press and hold the Volume (+) up and the Power (Sleep/Wake) buttons. Once your device turns on, let go of the buttons.
   * If you use a Samsung device, press the Power (Sleep/Wake), Volume (+) up and Home button.
   
   
3. Press the Volume up or Volume down key to navigate through the options. Highlight the Wipe cache partition then press the Power (Sleep/Wake) key to make the selection.
   
   

   

If none of the other solutions worked, reset your device to its factory settings. Resetting your device will remove the corrupt system files from your device and resolve other issues, too, caused by corrupt system files.

To reset your device to its factory settings, follow the steps below:

1. Backup your device's data to any cloud storage service (e.g. to Google Drive, Dropbox) or to a computer;
2. Go to Settings, tap on Reset and tap on the factory reset option;
   

   
   
   

The video guide below demonstrates how to reset your device (taken on a Samsung Galaxy device, running on Android 8 - the steps described may vary from one device to another):

Note: Make sure that your device is fully charged before resetting it, to avoid additional complications. Also, do make a backup of your personal files (photos, videos, music, and other documents), so that they are safely stored.