Q: How do I install or uninstall maps?
A: If you're on the Steam Workshop, just click the Subscribe button. For campaigns from Gamemaps, ModDB, Mediafire, or any other resource, download the file. Unpack the .vpk and put it in your addons folder. The directory is generally something like this: C:\Program Files (x86)\Steam\steamapps\common\Left 4 Dead 2\left4dead2\addons
Q: The same map is on the Steam Workshop and GameMaps. Which one should I get?
A: I used to always go for the Workshop version but now I will exclusively go for the GameMaps version for a number of reasons. First and most importantly, campaigns on GameMaps only come in one .vpk, meaning you won't have multiple parts even for a large campaign. Second, it takes a lot less time to load them than Workshop campaigns, and when you have a lot of add-ons, every little bit helps. Third, I can control when it updates. Lastly, it's likely to be a good, functioning version anyway so there shouldn't really be much difference (if any).
Q: I installed the map, but when I play, it crashes to desktop. What do I do?
A: First, read the map's description and check to see that you downloaded all necessary files. Some maps require additional or custom textures/sounds. If you have all the files, enable them all in the Add-Ons menu OR run the map with all other custom add-ons (including other custom maps) disabled. Check the comments to see if other users have had the level crash as well; maps with very low file size are likely to be incomplete or bugged. Lastly, you can always leave a message on the map page and hope the uploader or author responds to you.
Q: I installed everything correctly but I always crash on transition from one level to another.
A: Check to see if this only happens on campaigns that uses L4D1 survivors. If so, this is a known bug that may be resolved by typing "+precache_all_survivors 1" (without the quotes) into the game's command line or autoexec.cfg file.
Q: I installed the map, but when I connect to a dedicated server, I get an error message saying the server is enforcing consistency for a certain model.
A: Disable the indicated add-on or just disable all weapon model add-ons. Make sure you keep all add-ons related to the map enabled.
Q: I want friends to join me when I host a local server, but they always have to disabled their models or scripts because my server enforces consistency.
A: To stop your server from enforcing consistency, type in "sv_consistency 0" (without the quotes) into the console or into autoexec.cfg in your game files.
Q: I installed the map, but when I try to join a server, it just gives me a link to the map and tells me to download it again.
A: This error happens if you don't have the exact same version as the one on the server, even if one little point of reference (like the external link) is different. First, make sure the map is enabled in your Add-ons menu. If it is, try to see if it's conflicting with anything. If you have two versions of the map, try disabling the first and enabling the second. Otherwise you may have to download a newer or different version of the campaign.
Q: I installed the map, but when try to I join a server, I get an error message saying a server uses a different string table.
A: This means the server you're trying to connect to is using a different version of your map. Try to find out if there's a newer version of your map. If you do have the latest one, then either try connecting to a different server, start the game through a local server, or try again in a few days.
Q: I set up a server with a custom map but the loading icon just keeps spinning and it won't load!
A: Make sure the server type is set to Best Available Dedicated or Host Local Server.
Q: What are the most popular maps or the maps that are most likely to get people to join?
A: Click here.
Q: I installed multiple components in a collection but the Add-Ons menu highlights them all in red and says they all conflict.
A: Don't worry, you can still play the campaign. I don't know why this happens, but it's a well-known facet of some custom campaigns.
Q: When trying to start my own server, I can't find or select a particular custom map in the menu.
A: Make sure the map is enabled and doesn't conflict with anything. Try to see if it is selectable in survival or scavenge (it might not be a campaign map). Otherwise, it might not be in its proper alphabetical location; look for it throughout your list.
Q: I'm subscribed to a ton of custom maps and/or mods, and it takes forever for them all to load when I start the game! How can I reduce the loading time?
A: Move everything from your addons\workshop folder to your regular addons folder, then unsubscribe to everything you subbed to in the workshop (which is easy by searching the workshop by your subscribed items). Then you will have no loading time.
Q: What is your favorite map?
A: Dark Wood. With only a couple of exceptions, it illustrates the best of my criteria for a good map. Every serious map maker should play it, if not study it thoroughly to see what makes it good. I'm not saying it's the best map or that everything else is crap, but it is my favorite.
Q: What do you hate in custom maps?
A: Too many to list, but here are just some. Separate add-ons for custom content. Maps with missing textures. Maps with no scripted dialogue. Bland, boring, and overused environments. Maps with the "wrong" characters (the L4D2 group belongs in lighter and less heavy or serious maps, while the L4D1 gang belongs in darker, more serious and difficult ones). Maps whose parts conflict with each other or, worse, other unrelated mods, in the add-on menu. Terrible custom sounds or poorly recorded voices. Maps that have or require explanations beyond simple Game Instructor messages.