How to fix consistency errors

How to solve and fix consistency errors that pop up when attempting to join a game.

Consistency errors

Consistency is when a player's game files are identical to those of a server, and a server that is "enforcing consistency" is forcing all players' game files to match its own files.

Map string errors

A map string error is a consistency error that applies to the map that you are attempting to play; it means that one or more parts of the map you have do not match what the server has. This most commonly occurs in addon maps with their updated versions.

Official game file errors

Official game file errors will occur when your essential game files aren't the same as the server's, and will have the consistency error describing a file that is not a mod but something already part of your Left 4 Dead 2 files. With official dedicated servers, this commonly is caused by your own files being corrupt, although poorly made mods can interfere with your official game files.

Unofficial game file errors

This will not occur in servers not enforcing consistency (official dedicated and usually locally), but only unconfigured other servers.

Fixing consistency errors

Map string errors (Official maps)

Your game files are corrupt. Verify your files.

Map string errors (Custom maps)

Either your map or the server's is outdated.

Update your map to the latest version by checking the date on your game file and comparing it to the date of the last update on l4dmaps. If there is a new version, download and install this version, making sure to remove the old version (versions marked map1 will load before map2) from your addons folder; if this doesn't work or your map is up to date, the server's file is outdated; contact the admin/host of the server to update their map.

Game file errors (Official files)

Your official game files don't match that of the game, there are three reasons.

1- (Official dedicated and properly configured local host) Your game files are corrupt and you need to verify.

2- (Official dedicated and properly configured local host) You have a poorly made mod installed that is interfering with the official game files. This is rare with mods from l4dmaps, as that content is moderated, but can happen with mods from other sources or occasionally the workshop. If you verify your files and the error doesn't go away until you disable the mod, it is an issue with the mod and you should leave a comment on the mod page about the problem.

3- (Unconfigured local host) The server is enforcing consistency, tell the host to return to lobby and enter in the console this prior to starting

sv_consistency 0

Game file errors (Unofficial/mod files)

The local host is enforcing consistency, which it should not be. Tell the host to return to lobby and enter in the console this prior to starting

sv_consistency 0

Note concerning workshop mods

Recently, it has come to my attention that many workshop mods are causing weird consistency errors, even on official dedicated and properly configured servers.

Occasionally, mods can be poorly made and can interfere with basic gameplay; this is becoming unfortunately fairly common with workshop mods, since the workshop has very little moderation and the community that uses it is frequently very lax in calling out bad mods. If you've already tried the other steps in this guide and you're still getting errors on official servers, pay attention to the specific error it's giving you and disable any recent addons that have relevance, e.g. look for a hunter mod you have when you have a consistency error concerning the hunter.

If the cause of your errors are a mod you installed, I would encourage you to leave a comment on the mod page alerting the maker, downvote the mod, and please do report the mod to Steam.

If you are having this problem frequently, consider using l4dmaps for your game mods, as the strict moderation and community vigilance on that website means fewer low quality/bugged mods.

A few more helpful links

General guide to hosting local maps

Installing mods in Linux, so you Linux games can host your own custom campaign games. [url]A little extra: using a custom MOTD

[LeaKhoury]

Can you help me??? I tired the sv cosistency 0 thing and after that, I simply become unablale to do anything but move my camera on maps that I host and the error that I face is in Hunter's file

[Micro]

I putted that command but when I join a official server it just randomly resets the command:(

[ishmail23]

so i used the b2v misson script an back 2 vanilla addon but i comes up with a hunter error or something i need help

[April O'Neil]

To open the console, maje sure you have Enable Developer Console on, and press the tilda key (that would be the key next to tour 1 key)

[Stockholm14]

how i can open the console?

[Grizzly Goober]

I have no add-ons and it still won't work, I've verified files like 3 times

[Enfa]

I've a glitched bar when I grab some weapons, I can't play because it obstruct my fov. What could been causing it?

[PR(Y)DA]

Thanks dude

[Hamstirly]

Thanks for the help!

Was really putting a damper on me and my buddy's playing when things kept breaking.

[Raven]

I noticed that if it occurs with special infected it's always "$selfillum" parameter in infected's .vmt