http://doc.otrs.org/2.4/en/html/x834.html
that you have to make updates in this order :
But...where can I find those packages/files.These instructions are for people upgrading OTRS from "2.3" to "2.4".
If you are running a lower version of OTRS you need to follow the upgrade path to 2.4 first (1.1->1.2->1.3->2.0->2.1->2.2->2.3->2.4 ...).
Thanks.
Regards
Bruno