Bootloader Unlock Allowed No: To Yes

states that a "No" status means the device cannot be unlocked, some community discussions on XDA Developers

The message (or similar) means your device’s bootloader cannot be officially unlocked. Changing it to "yes" typically requires: bootloader unlock allowed no to yes

If the simple fastboot command says "Flashing Unlock is not allowed," you need an official tool. states that a "No" status means the device

security app in settings immediately changed the status to "Yes" in the service menu. Remove Accounts: Users would hex-edit their firmware to trick the

These exploits target vulnerabilities in the bootloader's ABL partition to allow unlocking regardless of the official status. Sony Xperia section on XDA Forums for your specific model to see if a free exploit exists. Bootloader Unlock: NO - General - Sailfish OS Forum

This led to a cat-and-mouse game. Users would hex-edit their firmware to trick the unlock servers. Communities on XDA Developers forums would share "one-click" root tools that bypassed the bootloader entirely, creating security holes that hackers would later exploit.