SM-G900P Downgrade Lollipop

I want to restore my phone to it's initial release.

I now have...
Android version: 5.0 (Lollipop)
Software version: G900PVPU3B0F6

I want...
Android version: 4.4.2 (Kit-Kat)
Software version: G900PVPU1ANCB

I've downloaded G900PVPU1ANCB from SamMobile.com
File name: G900PVPU1ANCB_G900PSPT1ANCB_G900PVPU1ANCB_HOME.tar .md5

I use ODIN to install, but there's an error...
Odin version: 3.09

Message log from ODIN:

<ID:0/004> Added!!
<OSM> Enter CS for MD5..
<OSM> Check MD5.. Do not unplug the cable..
<OSM> Please wait..
<OSM> G900PVPU1ANCB_G900PSPT1ANCB_G900PVPU1ANCB_HOME.tar .md5 is valid.
<OSM> Checking MD5 finished Sucessfully..
<OSM> Leave CS..
<ID:0/004> Odin v.3 engine (ID:4)..
<ID:0/004> File analysis..
<ID:0/004> SetupConnection..
<ID:0/004> Initialzation..
<ID:0/004> Get PIT for mapping..
<ID:0/004> Firmware update start..
<ID:0/004> SingleDownload.
<ID:0/004> aboot.mbn
<ID:0/004> NAND Write Start!!
<ID:0/004> FAIL! (Auth)
<ID:0/004>
<ID:0/004> Complete(Write) operation failed.
<OSM> All threads completed. (succeed 0 / failed 1)

Message log from ANDROID:

ODIN MODE
PRODUCT NAME: SM-G900P
CURRENT BINARY: Custom
SYSTEM STATUS: Custom
REACTIVATION LOCK(KK): OFF
KNOX WARRANTY VOID: 0X1 (4)
QUALCOMM SECUREBOOT: ENABLE (CSB)
RP SWREV: S1, T3, R1, A3, P1
SECURE DOWNLOAD: ENABLE
UDC START
SW REV CHECK FAIL : [aboot]Fused 3 > Binary 1

Any ideas as to why I can't downgrade? Thanks.