Help using transceivers in HDMI-port on Arria V GX starter board to send TMDS data

Might it have to do with constraints that I need to define in a .sdc file? I know nothing about this and can't find anything in the handbook about ut. I also have "a new project" based on the golden top where I just use a native PHY and try to send something over a single channel. Still the same (relevant) errors and warnings though:

Critical Warning (11087): PMA direct channel(s) detected and needs to be constrained based on the guidelines in Arria V Device Handbook Volume 3: Transceiver chapter
Error (175020): Illegal constraint of pin to the region (169, 23) to (169, 23): no valid locations in region
    Info (175028): The pin name: hdmi_tx_clkout_p
    Error (184016): There were not enough differential output pin locations available (1 location affected)
        Info (175029): pin containing PIN_AC3
    Info (175015): The I/O pad is constrained to the location PIN_AC3 due to: User Location Constraints (PIN_AC3)
Error (175020): Illegal constraint of Transmitter channel to the region (169, 11) to (169, 11): no valid locations in region
    Info (175028): The Transmitter channel name: hdmi_tx_p
    Error (175005): Could not find a location with: PMA_DIRECT_CHANNEL (1 location affected)
        Info (175029): Transmitter channel containing PIN_AJ3
    Info (175015): The I/O pad is constrained to the location PIN_AJ3 due to: User Location Constraints (PIN_AJ3)
Error (12289): An error occurred while applying the periphery constraints. Review the offending constraints and rerun the Fitter.
Error (11802): Can't fit design in device