I'm releasing a test function for GkevinOD's screencapture which is being used for Hide function. Just download it and run (make sure BlueStacks and Clash of Clans is open)
It will output 2 files:
capture.jpg is the screen capture of BlueStacks windows using the function
specs.txt is the specs of your computer (BlueStacks's resolution, Autoit version, OS specs, Desktop resolution, ...)
You can tweak around different windows setting (os version, color depth, resolution,..) and run it again to see if it works. It will output files in increment number so you know which setting works for you.
Please send in the logs together with a statement if it output a screenshot for you or a black image so we can isolate the issues
If you don't feel comfortable posting it here you can pm me or any other dev or not share it at all. But these informations will help us a lot in working on a fix. Thank you very much.
~Update: Added check for Aero