How can I reset to stock?

[AC Question]

Can't reset to stock

I have a Gs4. I rooted it about a week ago and went to the bathroom today and my phone was off and it was stuck on a bootloop. Kies is taking forever to connect and now it is stuck on the "firmware upgrade error" screen. I'm getting this error with Odin when trying to us a stock firmware:

<ID:0/006> 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 Successfully..
<OSM> Leave CS..
<ID:0/006> Odin v.3 engine (ID:6)..
<ID:0/006> File analysis..
<ID:0/006> SetupConnection..
<ID:0/006> Initialzation..
<ID:0/006> Get PIT for mapping..
<ID:0/006> Firmware update start..
<ID:0/006> sbl2.mbn
<ID:0/006> NAND Write Start!!
<ID:0/006> sbl3.mbn
<ID:0/006> rpm.mbn
<ID:0/006> aboot.mbn
<ID:0/006> FAIL! (Auth)
<OSM> All threads completed. (succeed 0 / failed 1)
<ID:0/006> Removed!!

Please help me. Thank you!