have forage harvester (tractor and trailing) picking up windrow in field in "last waypoint" mode forage harvester is full, CP driver stops and play-button goes grey I use AD to send forage harvester ...

Create a job with Courseplay on a field. For this instance I did a Liming job. Set Autodrive to Load mode. Select your field. Select the area where you store your Lime as the load point. Select Lime.