mobile

I would like to install whatsapp messenger on my samsung tab pro 8.4 that is wi-fi version. However, no matter which version of whatsapp messenger apk file that I downloaded to my tab driver and click open the file, the key of "next" / "install" couldn't work but only "cancel" key goes normal. I don't know why but my friend can install it smooth even at various non famous tabs of himself.

No response of the install key, and couldn't install the app to my tab, I don't know why, can anyone help me to solve the problem. Great Thanks !