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@YoYo Good to hear and glad you have it sorted out.
Yes, probably we find out the problem. I'm not an advanced editor and alpha channels are my nightmare.
I've tried it both with stock 'clear skies' and AS16. However, according to the thread that you pointed me to, my settings in AS16 might have been too aggressive.
@Delta558 Thanks. Just venting my frustration. Fortunately, I have Chase Plane.