I need help! Downgraded Bootloader/SGH-I337 - Soft Bricked

[MotoxMama13]

I'm sure you already know what I did....but I was unaware of the locked bootloader and when I attempted to go from Lollipop (5.0.1 I believe) back down to Kitkat (4.2.2), I soft bricked my phone. I've tried to flash the stock rom, no luck. I'm now stuck at (in recovery - which I do have but it's stock):

Failed to mount /system (invalid argument)
Can't mount /system (invalid argument)

I have a Galaxy S4 AT&T SGH-I337. I've wiped cache partition, factory reset...now I'm stuck! Any help would be GREATLY appreciated!

Thanks!

 

[Ammarasyad]

Sorry if this is a dead thread lol, but downgrading bootloader automatically tripped knox counter so it can't be flashed anymore. CMIIW

Posted via the Android Central App from my Samsung Galaxy S4 I9500