White screen when holding down mouse in Unreal Engine 4.6.1

Hello, I have a problem with unreal engine 4.6.1. The problem is whenever the mouse is held down the entire screen goes white, I don’t mind the flash when I click on the screen, but whenever I run my game in Unreal Engine build in gameplay tester the entire screen goes white!!! Is there anyway I can gameplay test my game outside of Unreal?? If so please tell me!

Computer Specs
macOS Sierra Version 10.12.2

Macbook Pro (13-inch, Mid 2012)
2.5 GHz Intel Core i5
16GB 1600 MHz DDR3 RAM
Intel HD Graphics 4000 1536 MB

Please help me, thanks in advance!