Doesn't allow to block the tank and other SI on a ladder.
How it works:
Around all ladders created trigger changes Collision Group player touching it. Supported only in the standard 4 L4D1 campaign mode coop and versus. And 2 DLC:
Crash Course and
The Sacrifice.
Cvars:
"l4d_showblock", "0", "1 - Show in chat if you have touched blocking area; 0 - Hide message".
Version:
v 1.0 (08 February 2015) - Plugin release (119 views).
v 1.1 (09 July 2015) - Added fix for Crash Course and The Sacrifice. Little fixes.