: The device has an updated security patch level (common on newer phones like the Infinix Smart 8 or ZTE A53 ), and the generic tool or old FDL files cannot bypass the secure bootloader.
The or "sending fdl2 fail" error is a critical hardware communication failure that occurs when specialized flashing and servicing tools fail to upload the secondary bootloader component ( FDL2.bin ) into an Android smartphone's temporary RAM . Commonly encountered on mobile devices running Spreadtrum/Unisoc (SPD) processors—such as budget models from Infinix , ZTE, Tecno, and Itel—this error completely halts crucial servicing operations like firmware flashing, PIN resets, and Google FRP bypasses. fdl2 failed
The -D (descriptor override) flag forces the tool to ignore some security checks. Use cautiously. : The device has an updated security patch