Quoting what I wrote on the project page -
Due to the “glow” maps (*_i.tga) changing from greyscale (8 bits per pixel) to rgb (24 bits per pixel) I thought it necessary to update parts of this. It is only parts because not all the downloads feature “glow” maps. Unfortunately, of the four to be updated one is the main download. For the majority of the things with glow maps I have simply removed the offending maps and updated the material files. Those glow maps would at best have been ignored by the graphics engine of NwN EE and at worst may have caused difficulties such as making the entire texture render as pure white. I haven’t removed all glow maps however. For a small number, where the glow map was essential for that texture, I have rebuilt the glow map in full colour (rgb). The result of this is that in the majority of cases the downloads involved are now slightly smaller.
The downloads involved are -
Main Texture Library PD
Limestone Pavement Texture
Hi Resolution Bricks Arranged in a Pattern (Single Texture)
40 Plant Textures
So if you have any of these, you really need to grab the updates, delete the old versions from your HD and only then install the new files. This is because in most cases we are loosing files, not adding them.
Project Page - Large Public Domain Fancy Mapped Texture Pack