Textures lump name issue?

[Hipshot]

So, this is strange. I have a clean mod, just a folder with a map and a model in it. When I define the model sprite name in the textrues file, called textures.txt, then the game crashes, zdoom won't start the mod. If I rename the file to textures.lmp the mod works and nothing crashes. The strange thing here is that this works well in another mod, that has a lot more assets... can it be that it's only for a model sprite and nothing else?

This is the mod, it's just a model test really: https://zfight.com/misc/files/shadowtest.zip

Edit: Uh, now it doesn't happen, just when I was actually about to verify this again...?