Help with Flashing Firmware

[FireDemise]

I recently bought a S8 Plus from China.
However this version does not include google play store, apps and It's in android 8.0
I wish to update this to android 9.0 and to the hong kong version however it's not letting me
it keeps saying security check failed: pit when I try to flash it. I even tried to flash the original firmware that was on the S8 Plus but it still doesn't work.

 

[mikedt]

S8 in mainland China is Qualcomm Snapdragon. Is it the G9508 variant you've got there? Hong Kong and international S8 is Exynos, and the firmware completely incompatible.

Have you managed to unlock the bootloader?