If you are a fan of Skylum's Luminar software like  I am, you may have been disappointed, like I was, if your experience with 4.0 was like mine. One of the main reasons to get 4.0 is the great improvements they've made in that AI photo manipulation.  One of the things they do that almost works like magic is the AI-based "Automatic Sky Replacement".  It does just what it sounds like, but it does it almost perfectly well and in a matter of seconds.  What would take me a good 15 to 30 minutes to do, you can now do with 2-3 clicks of the mouse. The problem is/was, that function on version 4.0 didn't work for me and judging from the comment boards, it didn't work for a lot of people. One thing I don't get about Skylum is they allow customers to post their bugs, complaints, and questions on the public-facing BBS, but they always send the answer directly to the customer via DM.  So you might search the board for help on sn issue, find that same issue posted