Connect your phone to your PC and run: adb reboot bootloader
If you receive an "unknown command" error, try the legacy command: fastboot oem unlock 4. Confirm on the Device Connect your phone to your PC and run:
If you are trying to flash a custom ROM or update your device via Fastboot and encounter the error FAILED (remote: 'flashing lock flag is locked. please unlock it first') , it means your device's . Enable OEM Unlocking Try the modern standard command
Modern Android security prevents unauthorized software changes unless the "lock flag" is explicitly flipped by the user. Here is how to fix this and successfully unlock your device. 1. Enable OEM Unlocking it means your device's .
Try the modern standard command first: fastboot flashing unlock
You cannot unlock the bootloader through a computer alone; you must first give the phone permission from within the Android OS. Open > About Phone .
After sending the command, your phone screen will likely change to a confirmation page. Use the to highlight "Unlock the Bootloader" and the Power Button to confirm. The device will then wipe itself and reboot. Troubleshooting Common Issues