Hello Oisin,
I have exactly the same setup (ADRV9002 EVB + ZYNQ-TPG3) when I use external LO, I get the same error, I'm using TES Argo Navis- 0.20.0 (the latest version) and my TES image is the latest one as well.
I have a square wave generator with quite low slew rate(33 ns rise time at 10 MHz). I applied 800mV Pk-Pk, 10 MHz square wave to EXT_CLK_IN interface and change the the clock reference switch position to external. But I'm getting this error as I tried to programm it with both LO configured to internal:
Kind Regards
Arash