In the middle of a driveable narrow slope stands a tree.
Harvester can't reach it from below or above. Though it's really close and all driveable up to the tree.
Expected behavior
Trees within harvester boom range should be possible to cut down.
We improved tree harvesting in Update 1, so closing as fixed. If this occurs in the new version again, please file a bug with a save file so we can take a look.