hi!
my unreal launcher has a black screen problem.
I re-setup newest DX and graphic driver.
but it still has problem 
3Ds Max and unity is good, just unreal4 is not good.
plz help me.
thanks.
Hi num1,
Check to see if you have any software installed that changes which graphics card is being used when a program opens. Nvidia Optimus on one of these programs.
Hi num1,
We haven’t heard back from you in a few days, so we are marking this post as resolved for tracking purposes. If you’re still experiencing this issue, please feel free to post back here with additional information.
Cheers,
TJ
I solved. 
My laptop have a switch graphics card.
I wanted to use Nvidia 970M. but It still showed me the black screen.
So I was using the integrated graphics card. And then I got the normal launcher.
thanks.
num1
Hi TJ Ballard.
thank you for your reply.
thank you for your help!
I solved!
please check my answer.
thanks. XD
Hello i have same problem but i tried all of this tips but nothing can somewho help me pls