Custom texture invisible in game

[JonnyAnomaly]

Thanks for the suggestions guys, but having deleted the map_cache files, its still not visible. I have the files "wallpaper1.dds" and "wallpaper1.mat" in a folder called textures in my custom story's folder, and also copied them to the main folder to make sure they didn't need to be there also. The map_cache files also recreate themselves whenever I start the game, but I assume this is normal. Its strange how its showing in the editor but not in the game...

Your Computer, I've been following your videos and they've been really helpful getting started, so thanks for those!

Edit - Its also disappearing whenever I reload the map in the editor, and the texture will only appear if I point it to the .mat which I originally placed into a folder called "custom stuff" in the redist folder. If I try to assign the same material from a different folder (the folder of my custom story) it will not appear in the editor. I had this with a gobo I was trying to use, but it fixed it once I had put the gobo into the folder with all the standard ones, although putting my custom material in with the others will not make it appear.