Failed -remote 39-flashing Lock Flag Is Locked. Please Unlock It First 39--

Once in Fastboot mode, run one of the following commands depending on your device's age: For newer devices (Pixel 2+, most modern phones): fastboot flashing unlock For older devices: fastboot oem unlock Step 4: Confirm on Device Your phone screen will change to a warning message. Use the Volume buttons to highlight "Unlock the bootloader" and the Power button to confirm. The device will then wipe itself and reboot. Troubleshooting Common Issues Flash with Fastboot - Android Open Source Project

Remove paper trays, look for stuck paper behind the fuser or near duplexer. Even a small scrap can hold a lock flag. Once in Fastboot mode, run one of the

Once you’ve successfully unlocked the lock flag, follow these best practices: Troubleshooting Common Issues Flash with Fastboot - Android

The error occurs when you attempt to flash firmware or partitions to an Android device while its bootloader is still in a "locked" state. Simply enabling "OEM Unlocking" in your phone's settings is not enough; you must also execute the specific unlock command through Fastboot. Step 1: Preparation (In Android) Simply enabling "OEM Unlocking" in your phone's settings