Likely the result of a prior iOS update which likely changed the device identifier and a subsequent update of TPControl from the App Store has now triggered turn TPControl a license validation problem.

Please let us know the 'Token' value within 'Settings > TPControl'

We can then assist you further in re-registering the device by providing you with the Tokens corresponding TPC User ID/email address.

If there is no Token value, you will need to contact your original AMX Integrator for details.