The review failure is a security block. You cannot proceed with the flash until you execute a specific unlock routine.
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 The review failure is a security block
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: Sometimes the standard unlock commands don’t work
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
Some bootloaders accept:
fastboot oem unlock-go
fastboot flashing unlock_critical
(Use unlock_critical to unlock bootloader and flash-critical partitions like xbl, abl.) The review failure is a security block
Conclusion
The "Failed -Remote 39:Flashing Lock Flag is Locked. Please Unlock it First" error, while frustrating, is a protective measure designed to prevent unauthorized modifications to a device's firmware. By understanding the causes and following the appropriate steps to resolve the issue, users and technicians can successfully overcome this hurdle. Always proceed with caution and ensure you have backups of critical data before attempting any firmware modifications.
Warning: Unlocking the flash lock flag almost always triggers a factory reset. All user data (apps, photos, accounts) will be wiped.
The operation failed because the system (likely an ECU, bootloader, or microcontroller) has a Lock Flag enabled. This is a security feature designed to prevent unauthorized writing or flashing of firmware.
This is not a Windows/MS Word “create paper” error. It’s a hardware lock error from the printer/copier.
Sometimes the standard unlock commands don’t work. Try these advanced techniques.