I tried using textures from Alien Vendetta, but this happens

When I decided to use Alien Vendetta textures in the level I am making, they work fine when I am testing the map in Doom Builder. But when I save the WAD and exti Doom Builder to play my WAD, I'll go to the AV textures I used. The AV textures are no longer there, instead, they are replaced with these black and white checkerboard wall textures. How do I fix this so that it will show the textures off of Doom Builder? I wanted to use the blue waterfalls from the level I am making. Thanks.

The checkerboard is there in certain ports to show that a texture used in the map is not available in the currently loaded resources. Are you loading the WAD with the textures in addition to your map?

If you loaded av.wad into doombuilder to use its textures, you'll need to load av.wad into the actual game itself or copy its textures to either a resource wad of your own or your own wad itself.

Yeah, that's what I'm doing. Any way I can just get the textures saved onto my WAD without having to load them?

Before doing so you should get permission from the creators of Alien Vendetta (if need be); I'm sure anders wouldn't mind if u can contact him that is. I can't recall if AV is free to rip without permission, i know they used a lot of duke3d and other resources, but there may be custom ones in there too. Worth investigating a bit.