CaptureScreenshot create black image

hi all!
in my script I’ve got this code:

 if (Input.GetKeyDown(KeyCode.K))
{
    var screenShot = string.Format("{0}/Shot.png", Environment.GetFolderPath(Environment.SpecialFolder.MyDocuments));
    Application.CaptureScreenshot(screenShot);
}

but retrieve a black image…
I put the code in LateUpdate or Update but the issue is in both situations.

I’m on dx11, unity 5.4.0p2 deferred linear mode…

thanks in advance!

might be of interest

(the two “non answer” replies I mean :slight_smile: )

for some context, the render loop is after all the game logic

thanks @LeftyRighty !
I’ve tried to do in a OnPostRender attached to a Camera but still black!

same thing here. i tried a whole bunch of scripts ppl had and I manage to get everyone to work, i get the screenshots but they are all solid black. Is this because of the Unity free version? or basic or whatever its called?