How to fix error code 18 on Google Play Store (Nothing else worked)

Every Android smartphone or tablet running on Android OS has a secret menu. This menu holds options that can help you regain access if you forgot the system password, if the operating system is stuck on the logo, if the operating system won't load. Among these options, there is an option to wipe the cache partition, which holds the key to fixing this error. Wiping the cache partition will wipe all the corrupt files on your device and replace them with their clean alternatives.

In order 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.
   
   

   

Maybe the latest version of the Google Play Store app is the cause of the error code 18, possibly because it was downloaded and installed improperly.

Revert the Google Play Store app to the default version, by following the steps mentioned below:

1. Go to Settings and select Application Manager/Apps;
2. Tap on Google Play Store, click on the three-dot icon in the upper right-hand corner, and select Uninstall updates;
   

   

3. Tap on OK to confirm; 
4. Open the Google Play Store app;
5. Update it, if prompted.
   
   

The video guide below demonstrates how to uninstall updates:

Note: The video 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 the other solutions didn't work, resetting your device to its factory settings may help. It will remove the corrupt system files from your device and resolve many issues along the way.

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;
3. Tap on Reset and tap on the factory reset option;
   

   
   
   

Feel free to watch the tutorial below, on 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.