I can't set up WhatsApp

[happyzenith]

Hi,

I've just downloaded OpenStore on my Meizu MX4 running OTA-15. I get a error message when I try to run it (after entering my phone number) which says something about it failing because it is an old version. I can't get the exact wording as it disappears from the screen really quickly.

Any ideas?
Thanks,
Naomi