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

Title

Failed -remote 39 — flashing lock flag is locked. Please unlock it first 39--

What It Means:

This error occurs when you try to perform an operation (e.g., flashing firmware, writing data, or modifying a device) while the device’s flash lock flag is enabled. The “39” likely refers to a specific error code from the tool or device firmware.

The flashing lock flag is a safety mechanism that prevents accidental overwriting or corruption of critical memory regions. It must be explicitly unlocked before any write/flash operation can proceed.

Unlock the lock flag

python mtk.py unlock

2. Detailed Technical Breakdown

To understand why this error occurs, one must understand the architecture of modern embedded flash memory (eMMC or UFS).

The Flash Memory Controller: Inside your device's storage chip, there is a dedicated controller. This controller manages how data is written, read, and erased. It does not simply accept commands blindly; it checks a specific configuration file or register known as the Flash Configuration (FC) or Device Configuration (DC).

The "Lock Flag": Think of the flash memory as a high-security vault. The "Flashing Lock Flag" is the digital equivalent of the bolt on the vault door.

State 1 (Locked): The controller ignores all "Write" and "Erase" commands sent from the external tool. It only allows "Read" commands (and sometimes, not even those). This is the default state for secure devices to prevent malware injection or unauthorized downgrades.
State 2 (Unlocked): The controller grants the external tool "Superuser" or "Root" privileges, allowing it to modify critical partitions like the bootloader, preloader, or primary firmware.

The error remote 39 indicates that your tool tried to force the door open without turning the key first. The controller responded with a NACK (Negative Acknowledgment) and the status code 39, signifying a permissions violation.

3. Why is the Flag Locked?

There are several reasons why this flag might be active:

Factory Default Security: Manufacturers (like Xiaomi, Samsung, or devices using MediaTek chipsets) ship devices with the bootloader locked to ensure the operating system remains unaltered.
Anti-Rollback Protection (ARB): Some devices implement a version counter. If you try to flash an older firmware version, the ARB logic triggers the lock flag to prevent the downgrade, protecting against known security vulnerabilities in older software.
Interrupted Flashing Process: If a previous flashing attempt failed midway, the device might have been left in a "Panic" state where the lock flag was engaged to protect the remaining data integrity.
Hardware Fuse (eFUSE): In high-security environments, a physical fuse on the chip might be blown during manufacturing, permanently locking the flag. If this is the case, software cannot unlock it.

If the Problem Persists:

Consult your device’s datasheet or flashing tool documentation for the exact unlock procedure.
Try a different flashing tool (e.g., dfu-util, openocd, vendor-specific software).
Some devices require physical jumper changes or shorting test points to reset flash lock.

This error occurs when you try to use to flash files onto an Android device (often Motorola or Lenovo) while the bootloader is still protected by a software lock. Essentially, the device's security prevents any unauthorized changes to its system partitions. Android Open Source Project 🛠️ How to Fix the Error To resolve this, you must follow these steps in order: 1. Enable "OEM Unlocking" in Android About Phone Build Number seven times to enable Developer Options Developer Options OEM Unlocking USB Debugging 2. Execute the Unlock Command Connect your phone to your computer via USB. Use the command adb reboot bootloader to enter Fastboot mode. Run one of these commands based on your device age: Newer devices: fastboot flashing unlock Older devices: fastboot oem unlock Android Open Source Project 3. Specific Case: Motorola/Lenovo Many Motorola devices require a unique Unlock Key Motorola Unlock Portal You will need to run fastboot oem get_unlock_data to get a string of characters to submit to their site. ⚠️ Important Warnings Data Loss: Unlocking the bootloader wipes all user data (factory reset). This process typically voids your warranty Your device becomes less secure against physical tampering. Android Open Source Project 💡 Troubleshooting Tips

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 Flash with Fastboot - Android Open Source Project

The error "FAILED (remote: '39-flashing lock flag is locked. Please unlock it first')" 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)

Before you can run the unlock command, your phone's OS must permit it.

Enable Developer Options: Go to Settings > About Phone and tap the Build Number (or MIUI version for Xiaomi) 7 times.

Toggle OEM Unlocking: Navigate to Settings > System > Developer Options and switch on OEM Unlocking.

Enable USB Debugging: While in Developer Options, turn on USB Debugging. Step 2: Enter Fastboot Mode Connect your phone to your PC via a USB cable. Open a terminal (CMD or PowerShell) on your PC.

Type adb reboot bootloader and press Enter. Your phone should reboot to a screen showing "Fastboot" or a similar logo. Step 3: Run the Unlock Commands

Try these commands in order. Warning: This will wipe all data on your device. For most modern Android devices: fastboot flashing unlock Use code with caution. Copied to clipboard For older or specific legacy devices: fastboot oem unlock Use code with caution. Copied to clipboard If the error specifically mentions critical partitions: fastboot flashing unlock_critical Use code with caution. Copied to clipboard Title Failed -remote 39 — flashing lock flag is locked

Note: Some devices will display a confirmation prompt on the phone screen. Use the Volume keys to select "Yes" and the Power button to confirm. Step 4: Troubleshoot "Unknown Command" If you receive a "Command failed" or "Unknown cmd" error:

Xiaomi/Redmi/Poco: You cannot unlock using standard fastboot commands. You must use the official Mi Unlock Tool after binding your Mi account in the Mi Unlock Status settings.

Motorola/Sony: These often require a unique "Unlock Code" obtained from the manufacturer's website.

Unisoc-based devices: Standard commands often fail; you may need a specialized tool like the TomKing62 CVE Unlocker.

Drivers: Ensure the Google USB Driver is installed. If your PC says "waiting for device," check your Device Manager to ensure the phone is recognized as "Android ADB Interface". Step 5: Verify Status To confirm your device is truly ready for flashing, run:

This error typically occurs when you're trying to flash a system image or custom recovery via , but your device's bootloader

is still locked. Android prevents any unauthorized changes to system partitions unless you explicitly "unlock" this security flag first. ⚠️ Warning Unlocking your bootloader will factory reset your device and wipe all data . Back up everything before you begin. How to Fix the "Flashing Lock" Error Step 1: Enable Settings in Android

You can't unlock the bootloader through commands alone; you must first allow it in your phone's software. About Phone Build Number 7 times until it says "You are now a developer!". Go back to Developer Options OEM Unlocking USB Debugging

Note: If OEM Unlocking is greyed out, connect to Wi-Fi and wait. Some carrier-locked phones (like Verizon or AT&T models) may permanently block this option. Step 2: Enter Fastboot Mode Connect your phone to your PC via a USB cable.

Open a terminal (Command Prompt/PowerShell) on your PC in your Platform Tools folder adb reboot bootloader

Your phone will restart into a screen that often shows a lying-down Android robot. Step 3: Run the Unlock Command

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

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 State 1 (Locked): The controller ignores all "Write"

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')" indicates that your device's bootloader is currently locked, preventing you from flashing custom partitions like recovery, boot, or system.

To resolve this, you must explicitly unlock the bootloader through the following steps: 1. Enable "OEM Unlocking" in Android

Before using fastboot commands, you must authorize the device to be unlockable: Go to Settings > About Phone.

Tap Build Number (or MIUI Version on Xiaomi) 7 times to enable Developer Options.

Go to Settings > System/Additional Settings > Developer Options. Toggle OEM Unlocking and USB Debugging to On. 2. Execute the Unlock Command

Once enabled, reboot your device into Fastboot Mode (usually by holding Power + Volume Down while booting) and connect it to your PC. Use one of the following commands based on your device: Standard Android: fastboot flashing unlock. Older Devices: fastboot oem unlock.

Critical Partitions (if needed): fastboot flashing unlock_critical.

Warning: Unlocking the bootloader will wipe all user data (factory reset) for security reasons. 3. Device-Specific Requirements Some manufacturers require additional proprietary steps:

Xiaomi/HyperOS: You must bind your Xiaomi account in the "Mi Unlock Status" settings and use the official Mi Unlock Tool on a PC. There is often a mandatory waiting period (e.g., 168 hours).

Google Pixel: Most allow unlocking immediately via the standard command unless they are carrier-locked (e.g., Verizon models).

Unisoc Devices: May require specific scripts or third-party unlockers to bypass the lock flag.

Are you using a Xiaomi device, or a different brand like Google Pixel or Motorola? Fix Device State Locked Unlockable in Fastboot Mode

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. If your device appears

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:

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

Part 5: How to Unlock the Flashing Lock Flag (Step-by-Step)

The exact command depends on your device manufacturer. Below are the most common methods.

5.4 For Samsung Devices

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

Enable OEM Unlocking in Developer Options (if grayed out, set date 7 days back and check again).
Reboot to Download Mode (Volume Down + Bixby + Power on older models; Volume Down + USB connect on newer).
Long-press Volume Up to enter unlock mode.
Use:
```
heimdall flash --RECOVERY twrp.img --no-reboot
```
Or with Odin: flash a patched vbmeta and unlock token.

4.4 Verify Bootloader Mode

Connect your device in bootloader/fastboot mode and run:

fastboot devices

If your device appears, proceed. If not, troubleshoot drivers.