Use this thread to report any bugs or issues you come across.

When reporting something, include as much information as possible; Even if you don’t think it’s relevant or useful. Bugs can have the weirdest reasons for happening, so the “probably unimportant” piece of information you might leave out could actually be the exact reason why it happens.
Even something as seemingly unimportant as the amount of time you've been playing for can be useful to know - It’s always better to provide too much information than not enough.

Also, if possible, include screenshots or video recordings of the issue, as this significantly helps figure out what went wrong.

Please also ensure that you can identify if the issue is due to a mod, or whether it happens with a completely unmodded game. This information is crucial in figuring out how to fix a problem.



This happens because of the amount of custom assets used in the campaign. The more custom models/textures/sounds a map has, the longer it will take to load - There is nothing that can be done about this.
The loading times will be different for everyone, as it depends entirely on the PC’s specs. Even with my PC it takes around 30 seconds to lead into each map, and playtesters on ancient hardware have even taken up to 3 minutes or longer to load.
Just like in the base game, having programs running in the background will also affect this, as will the amount of active add-ons.
In general, expect loading times to be 30% longer than with the official maps.


L4D2 is an old game, and therefore has very low engine limits. For example, it only allows 3.5GB of RAM to be used, even if you have more installed, and when you reach that limit the game will crash without any error message.
The game also has a limit of 256mb for sounds and models, which is very easily reached since Cold Front has almost 4000 custom models, sounds, and textures.
The best thing to do is to reduce your active mods: HD mods, RNG mods, custom campaigns, and any large Add-On over 100MB are likely taking up the most resources and should be disabled. You can type mem_dump into the console to see the current limits.
Adding -heapsize 750000 to the game's launch options will increase the model and sounds memory limit, which should alleviate some issues.


This happens when too many brush faces are visible at once, and as a result the game starts culling and unrendering the furthest brush faces. However, this is hidden behind the fog, so while it is a legitimate error, it has no effect on gameplay or visuals, and can be ignored.
If you encounter this error on your own map, you can fix it by lowering the render distance, or by turning chunks of brushwork into brush entities.


Left 4 Dead 2 does not support custom subtitles, at least not in Add-Ons. The accessibility patch remedies this, but requires external installation. It can be found here.


Due to how Mike’s voice was set up, his subtitles will display as Bill’s. This is unavoidable as the game lacks proper NPC and subtitle support. The aforementioned accessibility patch modifies this.


There is no way to do this, as the game is not set up to actually support NPCs. The only way to give him a HUD icon would be to overlay it with vscript, but that would not align with custom HUD mods.


This is normal. Mike is not supposed to be a playable character and the game is designed for 4 players, so taking control of him breaks all sorts of things.
You have to go out of your way to do this though, and there’s no reasonable way to prevent players from taking control without outright blocking the console commands, which would be a bit excessive. Just don’t do it and you’ll have no problems.
If this is a problem for dedicated servers, you can disable info_gamemode on map 3, and trigger the remove_mike_relay to prevent him from spawning.


This is an issue with the engine itself, and seems to affect all custom campaign finales. It appears to be completely random, and only unrenders prop_dynamic entities. I suspect this may be due to the ancient engine limits being reached.
One way of fixing this is to change your display mode in the settings, save it, and then change it back. No idea why this works, but if the invisible models really bother you, this is a quick fix.
I've also been told that starting and stopping a demo recording can fix it as well, but haven't been able to confirm this.


For optimization purposes, certain models do not render on lower graphic settings. This includes all the snowpile models. However, not every snowpile is a model, so only the ones that are will unrender.
The same optimization method was used for other models, such as debris, car glass, etc. - These will intentionally not render on lower graphics settings in order to boost performance.


I’m not entirely sure why this happens, but I suspect that it’s an engine issue. Unless anyone knows how to fix it, there’s nothing I can do.


Not sure why this happens, but it seems to be something with the engine itself. It’s not consistent either. Likely related to the game being 32-bit.


Unfortunately, unlike models, overlays are hard-coded to fade out based on the fog distance. When the storm happens, the fog comes in really close, which pretty much sets the overlays fade distance to 0, unrendering them completely.

This happens when using the VScript Heavy Rain mod. Use this version instead.


If you, by chance, do know any methods for fixing these issues, let me know in this discussion post.