Hi @jespa007, thanks for your patience whilst I investigated the option to use the Tobii Pro SDK in conjunction with the Tobii ET5.
Unfortunately, Tobii Pro are not supporting the use of this tracker with their Pro SDK so whilst you can continue to develop using the 4C (With the unlock licence) this does not extend to our new ET5 which is designed for gaming and interaction purposes only.
Our apologies for any inconvenience this has caused you. Please do let us know if we can provide any further information. Best Wishes.