How to stop these hacks?

In my rp server some ass always joins and has to ruin the fun. They will do stuff like change the skybox texture and spawn a bunch of effects which are blocked. At first i thought this was hacks, but i recently found that the whole skybox thing is from the door tool! Someone was nice enough in the server to show us what they were doing. But now the people that know how to do this stuff keep coming in the sever and spawning effects and admins can’t even touch these. Do any of you know how they could be doing this?

If you already know that the door tool is the source, why can’t you just delete it?

maybe if you read the whole post you would understand.
“But now the people that know how to do this stuff keep coming in the sever and spawning effects and admins can’t even touch these. Do any of you know how they could be doing this?”

I said the door tool is how they change the skybox…

then remove effects from being spawnable.

how is he wrong?

and why would the thread title be about stopping hacks when you’ve discovered that no hacking is involved?