How to install core GMS packages to use Google Play Store? I am having an issue with my brand new phone Huawei Mate 9 EMUI 5.0 from China. Somehow, when I want to install WhatsApp on it, I get the following message

Install core GMS packages to use Google Play Store

Here is the screenshot

What can I do to solve this? I just got the phone and I am lost.
I can well remember that Huawei devices can be added with GMS by flashing a flashable GMS package.

You'll need to first find a compatible 3rd party recovery for your phone. IIRC TWRP is (unofficially) available for Mate 9, so you can take a look at XDA Developers Forum.

After flashing recovery, go to OpenGApps and download a package that's suitable for your device (arm64-7.1-pico) and flash it via recovery. Voila! You now have GMS and Play Store on your device!