Kies has decided your phone csc doesn't match the update.
I've never used kies so can't help solve problems with it, apart from recommend you uninstall it.
If your csc has really changed, I've read that the 4.3 update can cause this, then you can download the full rom for your country from sammobile. Check the md5 then flash using odin (remove kies first), factory reset from recovery and the csc will then be set.
CSC is pretty useless for most people, it just seems to complicate Samsung issues.
Note: This quote doesn't automatically apply to everyone, decide for yourself if it might apply to you.
Originally Posted by justruss
What has this place become?
It's essentially a few people graciously answering the same repeating of immature, lazy, demanding questions from the masses.
Nobody searches. Nobody reads the first posts or titles of threads. Nobody even looks at posts a couple above their own.