Imported pictures don't show up in-game, PLEASE help D;

[Wrathborn771]

Hi,
I have made a thread a few days ago asking how I import pictures into a custom story (http://www.frictionalgames.com/forum/thread-16352.html), but I've stopped getting answers a few days ago, and my deadline is getting tighter and tighter..
If you please could take a few minutes of your life and read that thread and try to help me, it would mean the world for me.

So this is how I have it right now:
I've got 2 pictures, I've opened ModelEditor and made a SolidDefuse of both of them, and created two .mat files for them. I then copy+pasted them in my ´billboards´folder in my custom story redist, with both the .dds pictures and the .mat files.
I opened LevelEditor and pressed O, which opens the decal-tab, and I browsed to the ´billboards´folder in the Amnesia redist, then selecting one of the pictures and finally put it on both the wall and floor. None showed up. I went to the LevelEditor again and tried with the other picture, that didn't work either.

So now I'm here at the forums again, looking for help.
Thank you for reading this, I really appreciate your time.

Cheers
-Wrathborn