I've done two tree caches recently, which I personally had no problem with, but I could see from previous logs that others did. Neither cache description said that the cache would be high up a tree.
One, with a difficulty level of 3 and a terrain level of 3, was a 10 minute walk from the road up a hill and through a gulley. I gathered from previous logs that it would be in a hunter's tree stand and it was. The container was in plain sight about 25 feet up. Screw-in pegs were in the tree to get up there.
The other cache had a difficulty level of three with terrain of 3 and a half. It was a two and a half mile hike from the parking area. Previous logs led me to believe it was in or near a tree. The tree could have sheltered a cache, but the only real spot in it was about twelve feet up with no way to climb it. Nah, it couldn't be there, I thought. After looking everywhere else, I thought I'd better check it. Then I realized there was a large stick stuck in the ground that just happened to lean in the right place to use as a support. (A second, lighter searcher would have helped here.) It was still a blind reach into the hole, but there was the cache. I could see from the DNF logs that otheres were irritated to walk out so far and not find anything. And the hint was, "will send a spoiler picture upon request." (That's a whole other topic, right there.)
I had fun getting challenged by these, but a little heads up might be nice.