[Q] Help Rooting Verizon Galaxy S4 topic

Hi,
This is my first post on XDA, and I'm rather new to the site so if I'm posting in the wrong section, please let me know. Also, if I need to add any additional information, again, let me know.
I've been trying to root my Verizon Galaxy S4 for a little while now, and for some reason, every time I attempt to flash an older kernel onto my device, it fails and I don't know why. I am rooting my phone by following the instructions in this video: How To Root Samsung Galaxy S4 Android 4.4.2 EASY!!! (XDA is not letting me put the URL in the post due to the fact that this is my first post.) The video is by Sam Pullen.
Below is all of my information for my phone.
Model Number: SCH-1545
Android Version: 4.4.2
Baseband Version: I545VRUFNK1
Kernel Version: 3.4.0
dpi@SWDD6215 #1
Tue Nov 4 23:03:49 KST 2014
Build number: KOT49H.I545VRUFNK1
SE for Android status: Enforcing
SEPF_SCH-I545_4.4.2_0027
Secure boot status: Type: Samsung
Security Software version: MDF v1.0 Release 3
VPN v1.3 Release 2
My issue is that on my device, whenever I attempt to flash a new kernel to it, the readout on my device is Secure Magiccode Check Fail: Recovery
Any help with this would be greatly appreciated.