Originally Posted by Manthan Gohil
So no other way except formatting internal? Also miflash has option of keep data, will it keep my bootloader unlocked? And the latest stable Oreo fastboot ROM hasn't come out yet right?
You are jumping from beta to stable. Anytime you flash from beta to stable or vice versa, you'll need to format internal storage. That's how MIUI stupid policy works.
Even if you flash the fastboot rom via Miflash using option to keep data, it'll still ask for the password when you boot and eventually you'll have to format internal storage. It'll be a long process. Instead, use twrp now and format internal storage. Sorry for your loss.
Bootloader will remain unlocked when you use Mi flash. The latest stable is already out, wait for the fastboot links as they will be posted shortly which is 10.0.4.0 based on Oreo. The beta version is now based on Pie.