I am trying to compile the NativeEthernet / UDPSendReceiveString example from teensyduino for a teensy 4.1 and I get a strange error:
Error while detecting libraries included by C:\Program Files (x86)\Arduino\hardware\teensy\avr\libraries\FNET\s rc\service\serial\fnet_serial.c
The code that I am developing have the same problem
Doesn't do it on the example through normal ethernet / UDPSendReceiveString library.
I am running with Arduino 1.8.13 and Teensyduino 1.53

Any idea?