[AT&T, Rogers, Bell, Telus Samsung Galaxy S III] logoster:
ok, so i needed something from before cm12 today, did as you said, factory reset, then format data, i then restored from backup

while i did get into android, i kept getting all sorts of messages of "APPNAMEHERE has stopped" and after going to settings i couldn't get back to the home screen, everything was broken

decided to just do what you said, except this time flash http://xdaforums.com/galaxy-s3-att/general/rooted-ucufnj1-stock-rom-t2985006 this instead (and yes i am sure my phone is ucufnj2) and it always got stuck at the end of the AT&T boot logo, so i tried your way again, except this time the flash failed and it said something about "E: command not found", i was able to reflash cyanogenmod though, but i'd like to be able to get my touchwiz back

you know what, don't want to deal with this, how do i get my phone back to normal, i've never had a problem with touchwiz, it's not slow (or at least not nearly as slow as people say it is) and it worked pefectly fine for me, so how the hell do i get this backup to work correctly (i did have some apps on my external sd card, but AFAIK they weren't removed as the same amount of storage space is still being used

according to the TWRP log this is what's happening:

I:operation_start: 'Flashing'
Installing '/external_sd/roms/samsungofficial/UCUFNJ2_rooted.zip'...
Checking for MD5 file...
Skipping MD5 check: no MD5 file found
I:Zip does not contain SELinux file_contexts file in its root.
I:Legacy property environment initialized.
Register_libbootloader_updater Qcom msm8960
Register_libbootloader_updater Qcom msm8960
no file_contexts in package
Creating filesystem with parameters:
Size: 1572864000
Block size: 4096
Blocks per group: 32768
Inodes per group: 8000
Inode size: 256
Journal blocks: 6000
Label:
FLEX_BG size: 16
Blocks: 384000
Block groups: 12
Reserved block group size: 0
Labeling /system/ as u:object_r:system_file:s0
Created filesystem with 11/96000 inodes and 12038/384000 blocks
warning: wipe_block_device: Wipe via secure discard failed, used discard instead

Wipe(discard) takes 1 secs and 591424 usecs.
Extracing stock system.img... Please be patient, this will take several minutes.
minzip: zlib inflate call failed (zerr=-3)
minzip: Can't extract entry to file.
package_extract_file: install error 6
script aborted: assert failed: package_extract_file("system.img", "/dev/block/mmcblk0p14")
E:unknown command [install_error]
assert failed: package_extract_file("system.img", "/dev/block/mmcblk0p14")
I:Legacy property environment disabled.
E:Error executing updater binary in zip '/external_sd/roms/samsungofficial/UCUFNJ2_rooted.zip'
Error flashing zip '/external_sd/roms/samsungofficial/UCUFNJ2_rooted.zip'
Updating partition details...
I:Data backup size is 6126MB, free: 5866MB.
I:Unable to mount '/usb-otg'
I:Actual block device: '', current file system: 'vfat'
...done
I:Set page: 'flash_done'
I:operation_end - status=1

ok, managed to get that unufnj2 rom to flash, i guess the one on my phone got corrupted somehow and deleting then re-copying fixed it, however i still only get a black screen with a bunch of "APP Has stopped working here"

that and the power options are the only things that work from touchwiz anymore, however cm12 still installs and works fine, so obviously it's not my phone, so what the heck is wrong with touchwiz