[Sony Xperia Miro, Tipo (Dual), J, E] curlyboi:
I have exactly the same problem.

Unlocked loader, flashed CM10 (first boot.img), then rebooted to recovery and flashed the rest of the CM10.

Now the system boots and works but no SIM card. I have the st26i_11.0.a.7.5_ce.ftf file but when I try to flash it,

this is what I get:

22/004/2015 14:04:11 - INFO - Flashtool Version 0.9.19.6 built on 21-09-2015 18:30:00
22/004/2015 14:04:11 - INFO - Executing search strategies to find proxy selector
22/004/2015 14:04:11 - INFO - No proxy found for IE. Trying next one
22/004/2015 14:04:11 - INFO - Proxy found for firefox
22/004/2015 14:04:11 - INFO - Syncing devices from github
22/004/2015 14:04:12 - INFO - Scanning devices folder for changes.
22/004/2015 14:04:17 - INFO - Pulling changes from github.
22/004/2015 14:04:17 - INFO - Devices sync finished.
22/004/2015 14:04:22 - INFO - Device disconnected
22/004/2015 14:04:25 - INFO - Selected Bundle for Sony Xperia J (ST26i). FW release : 11.0.A.7.5. Customization : CE
22/004/2015 14:04:25 - INFO - Preparing files for flashing
22/004/2015 14:04:29 - INFO - Please connect your device into flashmode.
22/004/2015 14:04:34 - INFO - Device connected in flash mode
22/004/2015 14:04:34 - INFO - Opening device for R/W
22/004/2015 14:04:34 - INFO - Reading device information
22/004/2015 14:04:34 - INFO - Phone ready for flashmode operations.
22/004/2015 14:04:34 - INFO - Opening TA partition 2
22/004/2015 14:04:34 - INFO - Current device : Unknown: Nov 12 2012/22:55:05 - YT9005DX2Z - Unknown: Nov 12 2012/22:55:05 - Unknown: Nov 12 2012/22:55:05 - Unknown: Nov 12 2012/22:55:05
22/004/2015 14:04:34 - INFO - Closing TA partition
22/004/2015 14:04:34 - INFO - Start Flashing
22/004/2015 14:04:34 - INFO - Processing loader.sin
22/004/2015 14:04:34 - INFO - Checking header
22/004/2015 14:04:35 - INFO - Flashing data
22/004/2015 14:04:37 - INFO - Loader : S1_Root_a8a4 - Version : R5D030 / Boot version : R10D030 / Bootloader status : ROOTED
22/004/2015 14:04:37 - INFO - Max packet size set to 64K
22/004/2015 14:04:37 - INFO - Making a TA backup
22/004/2015 14:04:37 - INFO - Opening TA partition 1
22/004/2015 14:04:37 - INFO - Start Dumping TA partition 1
22/004/2015 14:04:38 - INFO - Finished Dumping TA partition 1
22/004/2015 14:04:38 - INFO - TA partition 1 saved to C:\Users\curly\.flashTool\registeredDevices\YT9005DX2Z\s1ta\2015-09-22_02-04-37\1.ta
22/004/2015 14:04:38 - INFO - Closing TA partition
22/004/2015 14:04:38 - INFO - Opening TA partition 2
22/004/2015 14:04:38 - INFO - Start Dumping TA partition 2
22/004/2015 14:04:39 - INFO - Finished Dumping TA partition 2
22/004/2015 14:04:39 - INFO - TA partition 2 saved to C:\Users\curly\.flashTool\registeredDevices\YT9005DX2Z\s1ta\2015-09-22_02-04-37\2.ta
22/004/2015 14:04:39 - INFO - Closing TA partition
22/004/2015 14:04:39 - INFO - Ending flash session
22/004/2015 14:04:39 - ERROR -
22/004/2015 14:04:39 - ERROR - Error flashing. Aborted
22/004/2015 14:04:39 - INFO - Device connected in flash mode
22/004/2015 14:04:40 - INFO - Device disconnected
22/004/2015 14:04:42 - INFO - Device connected in flash mode
22/004/2015 14:04:43 - INFO - Device disconnected

Also, in the stderr.log

java.lang.NullPointerException
at flashsystem.X10flash.getFlashScript(X10flash.java:669)
at flashsystem.X10flash.hasScript(X10flash.java:738)
at flashsystem.X10flash.flashDevice(X10flash.java:753)
at gui.tools.FlashJob.run(FlashJob.java:42)
at org.eclipse.core.internal.jobs.Worker.run(Worker.java:55)

I also tried the Sony Emma flasher tool, which does not recognize the phone as ST26i (Xperia J)

as it should, but just as "Unknown".

It seems like the phone lost its way of identifying itself as a JLo, but it still boots ok into both

CM10 and CWM recovery and it works very well (except the SIM of course)