Trying to Flash Stock

[TOTtomdora]

Hi,
Yesterday I got a Galaxy S3 SCH-I535 from a friend who upgraded to a Note 4. He said the S3 stopped working.
So I've been trying to flash stock recovery with odin to no avail; it would get stuck on the "SAMSUNG GALAXY SIII" screen.
Earlier I tried these instructions: Root & Install CWM Recovery on Galaxy S3 SCH-I535 4.1.1 / 4.1.2
And now when I try to do anything, whether it's boot it up or enter recovery mode (download mode still works), I get a Verizon error about how they want me to take the phone to a Verizon store (does that mean the bootloader was unlocked?)
Any help would be appreciated.

Edit: can a mod move this to the Verizon forum? I accidentally posted this to sprint...

 

[TOTtomdora]

Can a mod close this post? I fixed it; downloaded the wrong stock image (i545 instead of i535, whoops)