Waypoints "By Flight" problem

[JRS]

I'm trying to use Waypoints "By Flight" with Maven Evo on a Mini 3 Pro (with a DJI RC-N1 controller and a Pixel 6A phone). I can plot the points, see the route on the map, and save the mission. But when I try to fly the mission, I get a message: a string of numbers with the words "Error," "core," and "emp" mixed in. Everything's up to date, I've turned everything off and on again, etc. Help, please.