It is the responsibility of the AMX integrator and|or end-user to ensure that they retain a reference of any TPControl Token value that has been purchased.
Touch Panel Control provides online management of all purchased Tokens via TPCloud, but may not be able to positively identify Token ownership in cases where integrators and|or end-users do not know their TPControl Token value.

We will endeavour to assist in identifying device|token matches if and where possible.
Specifically, in the case of iOS devices, this is limited to the possibility that Touch Panel Control may have a UDID (Apple Unique Device Identifier) reference stored on the licensing server from an earlier (pre-iOS7) registration of TPControl on the device - but this is not guaranteed.
An illustrated guide that will assist in retrieval of the UDID for the device, that we can then try to reference in our system, is available here iOS - How to get the device UDID.

TPControl token values are paired with a 'TPC Device ID' at the time of registration. TPC Device IDs are used to assist in the identification of devices and matching registration information for tokens.

iOS Platform
Apple no longer permit iOS developers to access UDID information, which as developers Touch Panel Control used to positively pair with TPControl tokens, at time of token registration.
We now pair tokens with a unique TPC Device ID based on software identifiers that Apple permit us to use. However, as the identifiers are software based, they are prone to change under certain conditions, not limited to the following:
· Upgrading from iOS6 or earlier to iOS7 or later prior to running at least TPControl v2.4.2.0 for iOS on the device.More details here: http://www.touchpanelcontrol.com/ios7-update
· Installing TPControl from the AppStore using a different customer Apple ID than when TPControl was originally installed on the device.
· Resetting the device to factory default, and not restoring from a backup of the device that contained TPControl.

Android Platform
In terms of TPC Device ID retention, Android devices are the “better of the bunch” in comparison to the other platforms. However, Android devices are not immune to changes and so the TPC Device ID may also change under certain conditions, not limited to the following:
· Installing a “Custom ROM” on the device.

Windows 8/RT Platform
Similar to Apple with iOS, Microsoft provide software-based identifiers. So, the TPC Device ID may change under certain conditions, not limited to the following:
· Installing across multiple user profiles
· Upgrading the operating system which may result in a reinstallation of the application from the MS Store

Ensure that a reference to the original token value is always available. Refer to the WARNING above for more details.
In some cases, even though the Invalid License warning appears, a token value may actually be available on the device. Check by reviewing:
· iOS: ‘Settings -> TPControl -> Version: Token'
· Android: ‘TPControl -> MENU/Settings -> Version: Token'
· Windows 8/RT: ‘TPControl -> (charm or Windows-key + C) -> Settings -> Advanced -> Version: Token'

Armed with the token value, to re-register the device first try the on-device 'Token Registration' option, which is available within Settings for TPControl. Only if prompted by that process will the token need to be ‘Deauthorized’ at which point you can use either the 'Token Registration' or 'TPCloud PIN' methods to register the device.