Batch allows you to save the token of your device on the dashboard. This is useful to send test push notifications to your device with one click from the campaign editor, to make sure your message looks great and everything works perfectly (e.g. image, deeplink, etc). The list of all saved tokens is available from the dashboard settings > Push settings.
In some cases, the dashboard may show an error when you try sending a test notification to your iOS or Android device, or to your web browser: "PUSH_TEST_ERROR : Unregistered".
This usually happens because the device token you saved in the past is not valid anymore. Each time you reinstall your app, Apple or Google reset your existing token and generates a new one for your device, invalidating the existing one.
In order to fix the issue, you will need to:
Go to the dashboard settings > push settings and delete the invalid token