Did all correctly.... Wipe success, but flashing in twrp r3 & r4 says error 7. Gapps install crcctly, only ROM alone not install properlyyeah same , its say about to upgrade our system, but that game is in Beta, check the review you may find this is common problem, may be that game is for selected official android device like google pixel, and nexus, Vulkan is growing now currently no scope today but its future.
But i am sure we have our device 7.1, and since android 7, its Vulkan
so now DON'T reply to this, its OFFTopic.
---------- Post added at 05:34 AM ---------- Previous post was at 05:13 AM ----------
Have you installed TWRP v3.0.2-r3 or v3.0.2-r4? if not? flash TWRP first.
if already, then advanced wipe system, data, cache, dalvik/ART cache (if error during wipe, reboot TWRP and do it again)
then first install ROM zip, and then Open Gapps.
follow instruction properly, it should work.