Sorry to hear that, but this is almost certainly caused by mods. It could either be mods you've personally installed or mods running on the server you're using, I'm not sure. I've played through Time to Die dozens of times by now and this has never happened to me. Try uninstalling gameplay mods and playing on a local server after restarting L4D2 and you might have better luck.

I'm having the same issue where I lowered the platform to call for the rescue, but nothing happens. No mods

is it possible to have this map updated? it always stuck on custom server, maybe adding timed absolute trigger on the lift thing outside the house?