Why am I getting error message 'App Check Failed' when trying to log into the One4all App on my iOS device?

App check is a security feature which your phone must pass to enable use of the One4all App. There can be multiple scenarios where app check might fail:

-Poor or unstable network connection

-Device is jailbroken or compromised

-One4All app not installed from the official App Store

-Incorrect device Date/Time settings

-Outdated or broken App Store services

-Corrupted app data or cache

Note this is not an exhaustive list of scenarios, but they are the most common ones.

These scenarios can be troubleshooted and resolved by following below steps:

-Ensure proper network connectivity

Toggle Airplane Mode ON and then OFF, or switch between Wi-Fi and mobile data

-Avoid using jailbroken devices

Jailbroken devices often fail App Check due to compromised system integrity

-Update iOS to the latest version

Go to Settings > General > Software Update, and install the latest iOS version if available

-Restart the device

A simple restart can resolve temporary connectivity or certificate issues

-Ensure One4All is installed from the official App Store

If not, uninstall and reinstall it from the App Store

-Check and correct Date & Time settings

Go to Settings > General > Date & Time and enable Set Automatically

-Clear app cache and reinstall

Offload or delete and reinstall the One4All app via Settings > General > iPhone Storage > One4All