[Upgrading, Modifying and Unlocking] xproblem:
hello.

As in thread I have problem to do sth with my cell. It's F8131 with GENERIC_35.0.A.1.227 and I want to install 41.3.A.2.24 CE1.

I downloaded F8131_1302-9940_41.3.A.2.24-R1E_Customized_CE1 by XperiFirm in flashtool and prapaired the FTF file. It do not want to install on my cell.

Log is:

07/059/2018 17:59:55 - INFO - Flashtool Version 0.9.21.0 built on 28-04-2016 22:00:00

07/059/2018 17:59:55 - INFO - Executing search strategies to find proxy selector

07/059/2018 17:59:55 - INFO - No proxy found for IE. Trying next one

07/059/2018 17:59:55 - INFO - Strategy firefox failed trying next one : No Firefox installation found

07/059/2018 17:59:55 - INFO - No proxy found for java. Trying next one

07/059/2018 17:59:55 - INFO - Syncing devices from github

07/059/2018 17:59:55 - INFO - Opening devices repository.

07/059/2018 17:59:55 - INFO - Scanning devices folder for changes.

07/000/2018 18:00:03 - INFO - Pulling changes from github.

07/000/2018 18:00:06 - INFO - Quietly closing devices repository.

07/000/2018 18:00:06 - INFO - Devices sync finished.

07/000/2018 18:00:06 - INFO - Loading devices database

07/000/2018 18:00:06 - INFO - Loaded 100 devices

07/000/2018 18:00:06 - INFO - Starting phone detection

07/000/2018 18:00:12 - INFO - Device connected in flash mode

07/000/2018 18:00:14 - INFO - Selected Bundle for Sony Xperia X Performance(F8131). FW release : 1302-9940_41.3.A.2.24_R1E. Customization : Customized CE1

07/000/2018 18:00:14 - INFO - Preparing files for flashing

07/001/2018 18:01:24 - INFO - Please connect your device into flashmode.

07/001/2018 18:01:24 - INFO - Opening device for R/W

07/001/2018 18:01:25 - INFO - Reading device information

07/001/2018 18:01:25 - INFO - Phone ready for flashmode operations.

07/001/2018 18:01:25 - INFO - Opening TA partition 2

07/001/2018 18:01:25 - INFO - Current device : F8131 - CB512A2Q7J - 1303-2326_R2A - 1300-5321_35.0.A.1.227 - GENERIC_35.0.A.1.227

07/001/2018 18:01:25 - INFO - Closing TA partition

07/001/2018 18:01:25 - INFO - Start Flashing

07/001/2018 18:01:25 - INFO - No loader in the bundle. Searching for one

07/001/2018 18:01:25 - INFO - No matching loader found

07/001/2018 18:01:25 - WARN - No loader found or set manually. Skipping loader

07/001/2018 18:01:25 - INFO - Max packet size set to 4M

07/001/2018 18:01:25 - INFO - USB buffer size set to 256K

07/001/2018 18:01:26 - INFO - Parsing boot delivery

07/001/2018 18:01:26 - INFO - Ending flash session

07/001/2018 18:01:26 - ERROR - Cannot decide among found configurations. Skipping boot delivery

07/001/2018 18:01:26 - ERROR - Error flashing. Aborted

07/001/2018 18:01:27 - INFO - Device connected in flash mode

07/001/2018 18:01:27 - INFO - Device disconnected

07/001/2018 18:01:32 - INFO - Device connected in flash mode

I also tries other option in newflasher v10 with files directly from XperiFirm (without *.ta files) but program shows problem:

"No usb device with vid: 0x0fce pid: 0xb00b !"

I think that locked (but able to unlock) bootloader makes that failure... I tries to unlock bootloader with many instructions and key from sony. But when I use fastboot it is waiting for device.

Aby ideas?? It was test phone on exposure in the store and it's 1303-2326	Service Exchange Unit.