Possible causes include the following:
- Not all smartphones, tablets and operating systems are supported. Please check this list for all systems that are supported.
- If your smartphone or tablet is set to 'Developer mode' or 'USB Debugging', the app cannot be installed. Disable 'Developer mode' and 'USB Debugging' and try again.
- If your smartphone is 'jailbroken' (Apple) or has been jailbroken in the past, the app cannot be installed.
- If your smartphone is 'rooted' (Android), the app cannot be installed.
Please also review the 'Security' section for more information.