Jeesh!!! I just went through an ordeal to get this to work.
I have VIVADO 2022.2
First I got the "BACKBONE" error which I tried first fixing by setting the CLOCK_DEDICATED_ROUTE to TRUE. Then I was able to produce a netlist, but when I ran the LWIP Echo Server there was no output even throught the SERIAL port!!!!
Then I tried changing the board file version to 1.0. Finally the Serial port started to work. But I then got the "unable to determine type of EMAC with baseaddress 0x40E00000" error which I was able to fix by changing the xadapter.c code as suggested above.
What I don't understand is why using the V1.1 of the board file, I was not able to even get the serial port to work. Really strange!!!!
I'm going to try the UDP function. Let's hope!!!
Thanks!!!