Samsung uses a different mechanism called OEM Lock and KG (Knowledge Guardian) State.

Manufacturers sometimes lock the flashing flag tighter in newer updates. Flash an older stock ROM (if allowed) first, then unlock.

A: Yes, but be absolutely sure you are running 100% stock, signed images. Locking with custom images can brick the device.

The review failure is a security block. You cannot proceed with the flash until you execute a specific unlock routine.

The error message "FAILED (remote: '39: flashing lock flag is locked. please unlock it first!')" is a common security safeguard encountered when trying to flash custom firmware, recoveries, or system images onto an Android device via Fastboot. It essentially means the device's bootloader is currently locked, preventing any unauthorized modifications to the system partitions. Why This Happens

Android devices ship with a locked bootloader to ensure only official, digitally signed software from the manufacturer can run. When you attempt a command like fastboot flash, the system checks a "flashing lock flag". If this flag is set to "locked," the operation is automatically rejected to protect the device from potential malware or unintended software corruption. Common Solutions

To resolve this, you must explicitly unlock the bootloader, which typically involves the following steps:

Enable OEM Unlocking: In your device's Settings > Developer Options, you must toggle on OEM Unlocking. If this option is greyed out, your device may be carrier-locked or require an internet connection to "check in" with the manufacturer's servers.

Use the Unlock Command: Once OEM Unlocking is enabled, reboot the device into Fastboot mode and use one of the standard unlock commands: fastboot flashing unlock (Standard for newer devices) fastboot oem unlock (Common for older models)

Confirm on Device: Unlocking usually requires physical confirmation by pressing a volume or power button on the device itself.

Data Warning: Be aware that unlocking the bootloader will erase all user data on the device as a security measure. Flash with Fastboot - Android Open Source Project

This error occurs when you attempt to flash a system image or custom recovery to an Android device while the bootloader is still in a "Locked" state . To proceed, you must transition the device state from

, which requires both a setting change in the OS and a specific command in Fastboot mode. Android Open Source Project Step 1: Enable OEM Unlocking (In Android OS)

Before the bootloader will accept an unlock command, you must permit it within the system settings. About Phone Build Number 7 times until you see "You are now a developer." Go back to Developer Options OEM Unlocking and toggle it

Note: For brands like Motorola, you may also need to request an unlock key from their official site Android Open Source Project Step 2: Enter Fastboot Mode Turn off your device. Volume Down + Power

simultaneously until the bootloader screen (often with a "lying down" Android robot) appears.

Connect the device to your PC using a high-quality USB cable. Android Open Source Project Step 3: Run the Unlock Command Open a command prompt or terminal in your platform-tools folder and run: For newer devices (2015+): fastboot flashing unlock For older devices: fastboot oem unlock Android Open Source Project ⚠️ WARNING: Unlocking the bootloader will factory reset

your device and erase all data. Confirm the action on the device screen using the volume buttons and power key. Android Open Source Project Step 4: Verify Unlock Status

After the device reboots back into Fastboot mode, check the status to ensure the "flag" is no longer locked: fastboot flashing get_unlock_ability (Should return fastboot getvar unlocked (Should return Fairphone Community Forum Troubleshooting "Remote 39" Failures If the command still fails with error code 39:

Lock and unlock the bootloader | Android Open Source Project

Dismiss Got it. On this page. Get into the bootloader. Unlock the bootloader. Lock the bootloader. Set lock and unlock properties. Android Open Source Project

The error "FAILED (remote: 'Flashing Lock Flag is locked. Please unlock it first!')" occurs when you attempt to flash firmware or system partitions using Fastboot while the device's bootloader is still in a "Locked" state. To resolve this, you must explicitly unlock the bootloader through a multi-step process involving device settings and terminal commands. 1. Enable OEM Unlocking

Before the device will accept an unlock command in Fastboot mode, you must authorize it from within the Android operating system. Navigate to Settings > About Phone.

Tap on Build Number seven times until "You are now a developer" appears. Go to Settings > System > Developer Options. Locate and toggle on OEM Unlocking and USB Debugging.

Note: On some devices like Xiaomi, you must also bind your account under "Mi Unlock Status" and wait for a specified period (e.g., 168–720 hours). 2. Enter Fastboot Mode

Connect your phone to your computer via a reliable USB data cable.

Open a terminal or command prompt in your Android Platform Tools folder. Run the command: adb reboot bootloader.

Alternatively, power off the device and hold Power + Volume Down until the Fastboot logo (often a mascot or text) appears. 3. Unlock the Bootloader

Once in Fastboot mode, use one of the following commands depending on your device's manufacturer:

Sometimes the standard unlock commands don’t work. Try these advanced techniques.

There are several reasons why this flag might be active:

This is not a Windows/MS Word “create paper” error. It’s a hardware lock error from the printer/copier.

Error Code: failed -remote 39-flashing lock flag is locked. please unlock it first 39-- Severity: High (Operation Aborted) Category: Security / Write Protection

Failed -remote 39-flashing Lock Flag Is Locked. Please Unlock It First 39-- May 2026