Exclamation flashing stock .ftf For Xperia V via flshtool error <????

hi every one i had unlocked bootloader < installed leaked jb4.3 ,,, i want to return to the stock .140
i was trying to flash the stock .140.ftf via flashtoo but it was giving me an error :


15/007/2014 03:07:49 - INFO - Please connect your device into flashmode.
15/008/2014 03:08:13 - INFO - Device connected in flash mode
15/008/2014 03:08:13 - INFO - Opening device for R/W
15/008/2014 03:08:13 - INFO - Reading device information
15/008/2014 03:08:13 - INFO - Phone ready for flashmode operations.
15/008/2014 03:08:13 - INFO - Current device : LT25i - CB5A1UJNL9 - 1266-3473_R8H - 1264-2336_9.2.A.1.131 - GLOBAL-LTE_9.2.A.1.131
15/008/2014 03:08:13 - INFO - Start Flashing
15/008/2014 03:08:13 - INFO - Processing loader
15/008/2014 03:08:13 - INFO - Ending flash session
15/008/2014 03:08:13 - ERROR - No loader found for this device
15/008/2014 03:08:13 - ERROR - Error flashing. Aborted

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what can i do about it ?
or how to return to the old .140 ?