You need a stock FTF that matches your region or a generic one. Do not use an "OEM" only file.
Download the latest stable version of from the official repository. Run the installer and extract it to your primary directory (typically C:\Flashtool ). 4. Locate the Correct FTF Firmware sony g3311 lock remove ftf
If you prefer an official method without manual FTF files, use the Sony Xperia Companion Software Repair and follow the prompts to "repair" the device. You need a stock FTF that matches your
Flashing an FTF to remove a lock erases everything : sony g3311 lock remove ftf