The zombie action FPS Left 4 Dead 2 has just been updated with several fixes, which are meant to improve the overall gameplay experience.
First of all, Valve introduced two small blockers that will prevent players from being stuck:
"- Swamp Fever – The Swamp: added additional self-terminating survivor-only blockers to the areas above the airplane wreckage to prevent players from skipping the airplane event;
- Cold Stream South Pine Stream: Added a small blocker next to a crate near the military truck near mid-level to resolve a minor stuck spot."
In addition, the update fixes some issues with the game and tools not launching on PCs with 16+ CPUs. Valve also fixed controller navigation in mutation menus. For the full changelog of the update head over to the original thread.