Bootloader not unlocked. Fix: Run fastboot flashing unlock (this wipes data).
In the 2021 era of modding, the standard procedure required the Android SDK Platform-Tools and an unlocked bootloader. The command is typically executed in the bootloader/fastboot mode: vbmeta disableverification command 2021
The primary command to disable Android Verified Boot (AVB) verification on Android devices via Fastboot is: Bootloader not unlocked
You tried to flash a non-vbmeta image (e.g., boot.img) to the vbmeta partition. Fix: Double-check the filename. It must be vbmeta.img . vbmeta disableverification command 2021