Bidirectional LVDS buffer "Can't place node -- node is a differential I/O node"

Hello,

I'm trying to connect a sensor to EP4CE40F23C7 Cyclone IV E FPGA.

It's supposed to be connected to a bidirectional LVDS drivers, I did the proof of concept with a board with such drivers and it works.

I would like to achieve the same thing without the middle board. The board supporting the FPGA have some FPGA pins directly connected to 2.54mm header pin, including U9 (IO DIFFIO_B13p) and V8 (IO DIFFIO_B13n). I intanciated the buffer_lvds_bidir via the Quartus wizzard and connected as follows :

	inst_buffer_lvds_bidir : buffer_lvds_bidir
 
		port map(
 
			datain  => sl_DATA_DV_j404,
 
			dataio  => io_sensor_data_p,
 
			dataio_b => io_sensor_data_n,
 
			dataout => sl_DATA_RC_j404,
 
			oe    => sl_DE_j404,
 
			oe_b   => not(sl_DE_j404)
 
		);
 

Here is the *.qsf extract :

set_location_assignment PIN_V8 -to sensor_data_n

set_location_assignment PIN_U9 -to sensor_data_p

set_instance_assignment -name IO_STANDARD "3.3-V LVTTL" -to sensor_data_p[0]

set_instance_assignment -name IO_STANDARD "3.3-V LVTTL" -to sensor_data_n[0]

set_instance_assignment -name CURRENT_STRENGTH_NEW 8MA -to sensor_data_p[0]

set_instance_assignment -name CURRENT_STRENGTH_NEW 8MA -to sensor_data_n[0]

set_instance_assignment -name SLEW_RATE 2 -to sensor_data_n[0]

set_instance_assignment -name SLEW_RATE 2 -to sensor_data_p[0]

And what I get stopping Fitter step :

Error (176172): Can't place node "sensor_data_p[0]" -- node is a differential I/O node

Error (171000): Can't fit design in device

Could you please guide me to what is the matter ?

Thank you,