Go ahead and patch your game to 1.13.  If you've placed anything in your override or custom UI folders, you should clear those folders out before applying the patch.  You can either use the in-game patcher, or use NWN2 Patcher, a handy tool released by a community member.  It not only allows you to patch offline, but also allows you to create an undo file in the event that you want to revert back to the previous patch.  I patched this way, and it was pretty easy, and worked great.  If you go that route, you'll need to download the patch from the Vault patch site (it's the last one in the English list ).