It's these:

http://dream-of-vue.de/start.php

These are textures that came off lemog way back and saved as .mats for Vue.  I don't believe they are version specific, as I can open the above OK in V6I.

Maybe try re-downloading from the above site & see what happens it could be what you have has become corrupted.

Wabe you might could help here since the site is all in German & I see they also have forums which do appear to be active.  I quickly glanced about & didn't see a Vue version specific identification anywhere obvious.