Hello everyone,
This is my first post to the forum. I’ve been flying with ardupilot for a very long time, started out with a 2.6 then a 2.8 and now on the Pixhawk. I’ve never had this issue before but I cannot write waypoints. It connects via mavlink fine through telemetry and through us. I can change parameters, write them and read them, but when I go to write waypoints it gives.me and error. It says set waypoints and never changes and then fails to set them. I did this last year no problem (hibernating for winter 
) but now I cannot send them to the quad. If anyone can help I would.much appreciate it.
It sounds like you’re using ArduPilot and not PX4, so you might want to ask in the ArduPilot forums instead. This forum is for the PX4 autopiot stack. This being said, could it be that you don’t have a SD card inserted and hence the waypoints can’t be saved? That’s just a guess.