Flashtool - Processing System.sin finished with errors

[BlueChinchillaEatingDorito]

I'm trying to reinstall the default Sony tft back onto my Xperia SP but every time I flash the device, it fails at this stage. Any ideas on how to fix this? Flashing tfts on this phone used to be a breeze as this device has had multiple versions of CM in the past. I've installed all the necessary drivers for Flashtool including the one for the SP from the Flashtool folder. The phone turns on but gets stuck on the Sony logo and then shuts itself off.

 

Flashtool log:

Spoiler

20/031/2016 15:31:05 - INFO  - Selected Bundle for Sony Xperia SP(C5306). FW release : 12.1.A.1.205. Customization : GENERIC-AM
20/031/2016 15:31:05 - INFO  - Preparing files for flashing
20/031/2016 15:31:12 - INFO  - Please connect your device into flashmode.
20/031/2016 15:31:14 - INFO  - Device connected in flash mode
20/031/2016 15:31:15 - INFO  - Opening device for R/W
20/031/2016 15:31:15 - INFO  - Reading device information
20/031/2016 15:31:15 - INFO  - Phone ready for flashmode operations.
20/031/2016 15:31:15 - INFO  - Opening TA partition 2
20/031/2016 15:31:15 - INFO  - Current device : C5303 - YT910PDMN9 - 1272-3352_R1B - 1272-3352_12.1.A.1.207 - GLOBAL-LTE_12.1.A.1.207
20/031/2016 15:31:15 - INFO  - Closing TA partition
20/031/2016 15:31:15 - INFO  - Start Flashing
20/031/2016 15:31:15 - INFO  - Processing loader.sin
20/031/2016 15:31:15 - INFO  -     Checking header
20/031/2016 15:31:15 - INFO  -     Flashing data
20/031/2016 15:31:16 - INFO  - Loader : S1_Root_7054 - Version : R5G006 / Boot version : R11B023 / Bootloader status : UNROOTABLE
20/031/2016 15:31:16 - INFO  - Max packet size set to 64K
20/031/2016 15:31:16 - INFO  - USB buffer size set to 512K
20/031/2016 15:31:16 - INFO  - No flash script found. Using 0.9.18 flash engine
20/031/2016 15:31:16 - INFO  - Opening TA partition 2
20/031/2016 15:31:16 - INFO  - Writing TA unit 00002774. Value : 01
20/031/2016 15:31:16 - INFO  - Closing TA partition
20/031/2016 15:31:17 - INFO  - Processing partition-image.sin
20/031/2016 15:31:17 - INFO  -     Checking header
20/031/2016 15:31:17 - INFO  -     Flashing data
20/031/2016 15:31:20 - INFO  - Opening TA partition 2
20/031/2016 15:31:20 - INFO  - Closing TA partition
20/031/2016 15:31:21 - INFO  - Opening TA partition 2
20/031/2016 15:31:21 - INFO  - Processing amss_fsg.sin
20/031/2016 15:31:21 - INFO  -     Checking header
20/031/2016 15:31:21 - INFO  -     Flashing data
20/031/2016 15:31:24 - INFO  - Processing amss_fs_1.sin
20/031/2016 15:31:24 - INFO  -     Checking header
20/031/2016 15:31:24 - INFO  -     Flashing data
20/031/2016 15:31:26 - INFO  - Processing amss_fs_2.sin
20/031/2016 15:31:26 - INFO  -     Checking header
20/031/2016 15:31:26 - INFO  -     Flashing data
20/031/2016 15:31:28 - INFO  - Processing cache.sin
20/031/2016 15:31:28 - INFO  -     Checking header
20/031/2016 15:31:28 - INFO  -     Flashing data
20/031/2016 15:31:34 - INFO  - Processing fotakernel.sin
20/031/2016 15:31:34 - INFO  -     Checking header
20/031/2016 15:31:34 - INFO  -     Flashing data
20/031/2016 15:31:37 - INFO  - Processing kernel.sin
20/031/2016 15:31:37 - INFO  -     Checking header
20/031/2016 15:31:37 - INFO  -     Flashing data
20/031/2016 15:31:43 - INFO  - Closing TA partition
20/031/2016 15:31:44 - INFO  - Opening TA partition 2
20/031/2016 15:31:44 - INFO  - Processing system.sin
20/031/2016 15:31:44 - INFO  -     Checking header
20/031/2016 15:31:46 - ERROR - Processing of system.sin finished with errors.
20/031/2016 15:31:46 - INFO  - Ending flash session
20/031/2016 15:31:46 - ERROR -
20/031/2016 15:31:46 - ERROR - Error flashing. Aborted
20/031/2016 15:31:46 - INFO  - Flashing finished.
20/031/2016 15:31:46 - INFO  - Please unplug and start your phone
20/031/2016 15:31:46 - INFO  - For flashtool, Unknown Sources and Debugging must be checked in phone settings
20/031/2016 15:31:46 - INFO  - Device connected in flash mode