Trying to get to stock from CM 11 with no luck

Hello!

So i've been failing at getting this SGS4 SCH-M919 back to stock firmware. I have CM11 nightly installed. (This is my bosses phone that i'm trying to get back to stock) So far, I've downloaded two stock firmware images (just in case firs was corrupt) and they both haven't worked.

My process goes like:
-Download drivers (or Kies, i've tried both)
-Set into recovery mode
-Start Odin (i've tried in a few versions)
-Plug phone in
-Odin recognizes
-choose file to flash
-Start the flash then I'll always get this error

<ID:0/005> Added!!
<OSM> Enter CS for MD5..
<OSM> Check MD5.. Do not unplug the cable..
<OSM> Please wait..
<OSM> M919UVUAMDL_M919TMBAMDL_M919UVUAMDL_HOME.tar.md5 is valid.
<OSM> Checking MD5 finished Sucessfully..
<OSM> Leave CS..
<ID:0/005> Odin v.3 engine (ID:5)..
<ID:0/005> File analysis..
<ID:0/005> SetupConnection..
<ID:0/005> Initialzation..
<ID:0/005> Get PIT for mapping..
<ID:0/005> Firmware update start..
<ID:0/005> sbl2.mbn
<ID:0/005> NAND Write Start!!
<ID:0/005> sbl3.mbn
<ID:0/005> rpm.mbn
<ID:0/005> aboot.mbn
<ID:0/005> FAIL! (Auth)
<OSM> All threads completed. (succeed 0 / failed 1)

After that, i'm in a little brick mode that I can easily get out of my flashing CWM Recovery on there, and it'll boot me back into CM11.

So, any ideas? I've tried two computers, restarted...idk what to do anymore.

Thank you to anyone who tries to help me!