SM-G900A Galaxy S5 AT&T Update to Android OS5.1.1

ro.build.id=LMY47X.
ro.build.display.id=LMY47X.G900AUCU4COI5.
ro.build.version.incremental=G900AUCU4COI5.
ro.build.version.sdk=22.
ro.build.version.codename=REL.
ro.build.version.all_codenames=REL.
ro.build.version.release=5.1.1.
ro.build.date=Tue Sep 22 21:38:37 KST 2015.
ro.build.date.utc=1442925517.
ro.build.type=user.ro.build.user=dpi.ro.build.host =SWHD4323.
ro.build.tags=release-keys.
ro.build.flavor=klteuc-user.
ro.product.model=SAMSUNG-SM-G900A.
ro.product.brand=samsung.
ro.product.name=klteuc.
ro.product.device=klteatt.

SM-G900A firmware corrupted

Hi, i recently got the SM-G900A from AT&T and the firmware corrupted. It was running stock lollipop with the build number G900AUCU4BOF3. At first i was on a screen where it said for me to "Connect to Kies and select Emergency Recover" or something, but my phone isn't supported nor does it show up on Kies. I have tried every stock version i could find to try and downgrade my build number if possible, but it would always fail in Odin.

Also, in Recovery Mode it shows a completely different build number: G900AUCU1ANCE


<ID:0/009> Added!!
<OSM> Enter CS for MD5..
<OSM> Binary Check MD5.. Do not unplug the cable..
<OSM> Please wait..
<OSM> Checking MD5 finished Sucessfully..
<OSM> Leave CS..
<ID:0/009> Odin engine v(ID:3.1100)..
<ID:0/009> File analysis..
<ID:0/009> SetupConnection..
<ID:0/009> Initialzation..
<ID:0/009> Get PIT for mapping..
<ID:0/009> Firmware update start..
<ID:0/009> SingleDownload.
<ID:0/009> aboot.mbn
<ID:0/009> NAND Write Start!!
<ID:0/009> FAIL! (Auth)
<ID:0/009>
<ID:0/009> Complete(Write) operation failed.
<OSM> All threads completed. (succeed 0 / failed 1)

The thing i don't really get is why it let me flash "system.img.tar" and it won't flash a full stock rom without the output above.. Any help would be greatly appreciated! If possible, can someone dump their stock rom?