Remove your "Textures" folder entirely and run the updater. Please note, that you have to select the option FULL CHECK in the upper left corner of the updater.
Stop your anti-virus while you do the full check.
If that doesn't help, you should try uninstalling your Lineage 2 client and find a fresh copy (your best bet would be rpg-club main website) and/or download the whole thing from the rpg-club updater.