That's what I tried testing out. I loaded several different maps that I've had no problem loading not long before this started happening.

Maps work fine in multiplayer, just not singleplayer.

I don't know if I'm the only one having this problem, but I cannot load a single map that has anything to do with TTT or run any map with TTT as the gamemode.

I just deleted my Garry's Mod folder and put back my maps folder and it's a no go.

Anyone got an idea?

I've been having people complaining about this on our server too.

Just because someone has an idea for TTT they're trolling? 

No, he posted this on our forums and I told him to come here and do it otherwise it would only be heard and never seen in-game.

I think it's a rather interesting idea although, I also don't see it being very helpful for detectives; I guess that would depend on how small the planted camera would be.  I mean, you wouldn't be able to see the player's name, but I guess you could see where stuff was going down and alert the rest of the innocents.

It's has potential for both being useful and ending up like the footprint tracker.  I'm leaning a little more on the useful side.