[Sony Ericsson Xperia Neo, Pro] lo2ay:
I'm trying to restore my Xperia Pro (MK16i) to stock ICS. Whenever I flash an ICS ftf file using flashtool it always fails at flashing the system partition. But GB ftf works just fine and it even boots. When searching for update from the phone after installing stock GB it says that there are no updates available. So I need to flash ICS manually (which as stated, fails)

05/014/2018 17:14:27 - INFO - Preparing files for flashing
05/014/2018 17:14:29 - INFO - Please connect your device into flashmode.
05/014/2018 17:14:33 - INFO - Opening device for R/W
05/014/2018 17:14:33 - INFO - Device ready for R/W.
05/014/2018 17:14:33 - INFO - Reading device information
05/014/2018 17:14:33 - INFO - Phone ready for flashmode operations.
05/014/2018 17:14:33 - INFO - Opening TA partition 2
05/014/2018 17:14:33 - INFO - Current device : MK16i - CB5A1KAFW9 - 1249-8108_R12D - 1243-7775_4.0.2.A.0.58 - WORLD-i_4.0.2.A.0.58
05/014/2018 17:14:33 - INFO - Closing TA partition
05/014/2018 17:14:33 - INFO - Start Flashing
05/014/2018 17:14:33 - INFO - Processing loader.sin
05/014/2018 17:14:33 - INFO - Checking header
05/014/2018 17:14:33 - INFO - Flashing data
05/014/2018 17:14:36 - INFO - Loader : S1_Loader_Root_773f - Version : R4A066 / Boot version : R9B031 / Bootloader status : UNROOTABLE
05/014/2018 17:14:36 - INFO - Max packet size set to 64K
05/014/2018 17:14:36 - INFO - USB buffer size set to 512K
05/014/2018 17:14:39 - INFO - No flash script found. Using 0.9.18 flash engine
05/014/2018 17:14:39 - INFO - Opening TA partition 2
05/014/2018 17:14:39 - INFO - Writing TA unit 00002774. Value : 01
05/014/2018 17:14:39 - INFO - Closing TA partition
05/014/2018 17:14:39 - INFO - Opening TA partition 2
05/014/2018 17:14:39 - INFO - Closing TA partition
05/014/2018 17:14:39 - INFO - Opening TA partition 2
05/014/2018 17:14:39 - INFO - Processing adsp.sin
05/014/2018 17:14:39 - INFO - Checking header
05/014/2018 17:14:39 - INFO - Flashing data
05/014/2018 17:14:42 - INFO - Processing amss.sin
05/014/2018 17:14:42 - INFO - Checking header
05/014/2018 17:14:42 - INFO - Flashing data
05/014/2018 17:14:51 - INFO - Processing amss_fs_iyokan.sin
05/014/2018 17:14:51 - INFO - Checking header
05/014/2018 17:14:51 - INFO - Flashing data
05/014/2018 17:14:51 - INFO - Processing cache.sin
05/014/2018 17:14:51 - INFO - Checking header
05/014/2018 17:14:51 - INFO - Flashing data
05/014/2018 17:14:53 - INFO - Processing fota0.sin
05/014/2018 17:14:53 - INFO - Checking header
05/014/2018 17:14:53 - INFO - Flashing data
05/014/2018 17:14:55 - INFO - Processing fota1.sin
05/014/2018 17:14:55 - INFO - Checking header
05/014/2018 17:14:55 - INFO - Flashing data
05/014/2018 17:14:56 - INFO - Processing kernel.sin
05/014/2018 17:14:56 - INFO - Checking header
05/014/2018 17:14:56 - INFO - Flashing data
05/014/2018 17:14:59 - INFO - Closing TA partition
05/014/2018 17:14:59 - INFO - Opening TA partition 2
05/014/2018 17:14:59 - INFO - Processing system.sin
05/014/2018 17:14:59 - INFO - Checking header
05/014/2018 17:14:59 - ERROR - Processing of system.sin finished with errors.
05/014/2018 17:14:59 - INFO - Ending flash session
05/014/2018 17:14:59 - ERROR - ERR_SEVERITY="MINOR";ERR_CLASS="PROTOCOL_CLASS";ERR_STATIC="PKG_SIZE";ERR_DYNAMIC="";
05/014/2018 17:14:59 - ERROR - Error flashing. Aborted
05/014/2018 17:14:59 - INFO - Flashing finished.
05/014/2018 17:14:59 - INFO - Please unplug and start your phone
05/014/2018 17:14:59 - INFO - For flashtool, Unknown Sources and Debugging must be checked in phone settings
05/015/2018 17:15:04 - INFO - Device disconnected