Issues when opening texture packs

[Yumheart]

I have problems using texture packs, cause whenever I try to open one in Slade, the textures just get completely messed up. It's probably just some stupid amateur mistake.

As far as I know, that's supposed to be a brown brick wall:

Does anybody have any ideas for troubleshooting? For reference, I'm using SLADE v3.1.12.

[snapshot]

Top Right, change Palette to the Doom or whichever game the texture pack is for.

[ViolentBeetle]

I think the palette might be missing entirely. You need to load DOOM.WAD as base resource, but I forgot how.

[Yumheart]

Yep, I'm stupid. Thanks a lot.