Weird Texture Error

First off, I wasn’t sure if this counted for help and support but I wasn’t sure if I should put it in general either, so I just put it here. I guess it is a gameplay problem sort of?
Anyway, I have half life 2 as well as the episodes installed, but for this one particular AR3 addon my textures show up as this:

The mod creator has no idea how to fix it, so does anybody here have an idea of what it could be?

Does the normal turret AR3 show up normally?

Turret AR3?

[editline]12th August 2015[/editline]

I’m pretty sure whatever turret textures you’re talking about are there, but a picture for what you’re talking about would be great. I still really need help, a texture download or something would be great if anybody finds the textures I need.

Can you post the gma here?

I’m not sure how to attach files.

Upload it to a file hosting service like mega or mediafire

http://www.mediafire.com/download/tgof5e028l2vhzu/combine_ar3_machine_gun_121412995.gma

Here