Unity Game Tab shows a static screen

Hi,

I am facing problem when i click play button in unity. The Game was loading automatically, but now i have to click it manually. But then its showing a static scree.

The message in console:
VideoTextureInfo 640 480 640 480
UnityEngine.Debug:Log(Object)
BGRenderingAbstractBehaviour:Update()

@pradeep3043, i think you are using Vuforia SDK. Please check your device camera (may b it is turned off).