Certain Props are not spawning and/or showing up as errors in spawn menu

Hello everyone,

Just to be clear, I have CSS, TF2, HL2, HL2: episodes one and two, HL:Deathmatch, HL: Lost Coast and Portal, HL: Deathmatch Source, L4D2 (all legal on Steam).

I’m working on a building in Gmod10 and when I searched for certain props which would be very useful, I could not spawn them or they showed errors in the spawn menu. These are nearly all the models that show up when I search ‘church’ in the spawn menu. A great deal of them are under models/props_italian or models/props_italian/anzio…

Does anyone have any idea what I might be missing?

You didn’t say you obtained Garry’s Mod legally. Did you pirate it?

No. Gmod is legal.

I think I figured it out. I believe those models I’m looking for are part of Day of Defeat: Source, which I don’t have.