*** Bug 896662 has been marked as a duplicate of this bug. ***
This looks like the same issue I'm experiencing. I removed the <packages*> section from your job and it submits. You have squid listed as a package to be installed there. You can work around this with the following: <ks_appends> <ks_append>yum -y install squid</ks_append> </ks_appends>
*** This bug has been marked as a duplicate of bug 896622 ***