Before diving into unlock methods, ensure the following:
To avoid re-encountering the error, do not run:
fastboot flashing lock
Unless you are returning the device to a fully stock state for resale or warranty. Before diving into unlock methods, ensure the following:
Use the standard fastboot flashing unlock command.
Steps:
You must remove the write protection before attempting to flash again. Here are the standard steps to do this:
Use a "Mass Erase":
Check for Physical Jumpers/Pins:
Power Cycle:
Warning: Unlocking the flash lock flag almost always triggers a factory reset. All user data (apps, photos, accounts) will be wiped.