[Q] Problem Updating From 10.1.2 -10.1.3

Hi. I am fairly new to this so the help is appreciated. I have been trying to upgrade my s3 R530 past 10.1.2 but the installation keeps getting aborted. It says something along the lines of: error: get prop boot loader. I know this isn't much to go off of so I will upload some info below. I have researched this problem and have hit a dead end. A friend of mine suggested that I flash back to the stock ROM and update my phone through us cellular. He thinks that there might be an update for the bootloader. The only thing is... I can't find a downloadable stock ROM. I am open to any ideas at this point. I will try the update again so I can provide more info on the error. Thanks!

Here is what my phone says when I try to update it.

Installing: /storage/sdcard1/phone upgrading/New Phone Update/cm-10.1.3 d2usc.zip
Finding update package...
Opening update package...
assert failed: get prop("ro.bootloader') == "R530 UVXAMD1" || get prop(ro.bootloader") == R530UVXAMD4
E: Error in /storage/sdcard1/phone upgrading/New Phone Update/cm-10.1.3-d2usc.zip
(Status 7)
Installation aborted

I hope that this helps.