Your Google Play Store may be out of date and will need to be updated. Open the Google Play Store App Tap Settings Scroll down to Play Store Version Tap to check for an update. If there is an update option select it and allow it to update Then try downloading the OTR Diagnostics App again If the app still will not download you may need to reset the Google Play Store. Follow the steps below. Go to your device settings Apps Tab Scroll down to Google Play Store Tap Storage Tap Clear Data Try to download the OTR Diagnostics App again If none of these work call our support team at 586-799-4375 or email at support@otrperformance.com