Hello, I have a problem with my map, I have made a zombie debris and when I test my map, the door/debris is invisible and I can walk straight through were the debris is supposed to be, but you can still buy the debris, so I would really really appreciate any help with this.

Create a script->brushmodel and size it however you want. Then give it a clip texture to make it solid.
The problem is, after you buy the door, you won't be able to walk through it. So we have to add some kvp's:

Kvp: spawnflags Key: 1
Kvp: script_linkTo Key: 1
Kvp: targetname Key: door

Change "door" to whatever the targetname is that you assigned to your debris. Normally "script_linkTo" should be "1" unless you changed it in your debris kvp's, if so then give it the same value.

WOW thank you so much, I just discovered what I did wrong because of what you told me!