Same..
sad thing is the add-on/MOD used to work

Why is it not all one file?

I keep getting these errors too, but the campaigns work fine on my end.

And to theblackwidower, it has something to do with memory limitations. While all the maps are about half a gigabyte when combined.

same problem. unsubscribing

this used to work for me also. its actully the only map i have downloaded aside from the campaigns. then one day went to go play it, and got the two or more files are conflicting error. when i go to uncheck them you can only have one of them checked. if you check another one in any order they turn red, and wont work :( any suggestions?

to get the textures to work, enable all 6 parts. It puts all the textures there. They conflict, but loading it anyway makes all 6 parts work.

If all 5 parts say their conflicting with only eachother then its fine, 50% of the maps on the workshop that have more than 1 part say they conflict but they still run fine so make sure to try it first, the conflicting is just the addoninfo file that needs to be the same so the engine knows to treat the parts as 1 campaign, although there is a way to fix it most map developers dont go through the effort. The workshop has Limitation On Uploads, and since l4d2 maps have so much content as a map you progress through, they have to be split into parts which is valves deal not the developers.

If your having crashing on a custom map then first try disabling all other addons in L4D2 and try again to see if it crashes, if it doesnt then start adding them back 1 at a time till you find which one it is, if it still crashes with all other addons off then try turning your Page Pool Memory and other graphics settings down first cuz sometimes the map developers put a little too much detail in and its hell on lower end systems, and if you have to turn your settings down to play without lagging on the default maps then theres a lot of workshop maps you just wont be able to run, so hopefully this helps someone.

Lo que yo hice fue en el bloque de comandos (que a mi siempre me aparece al arrancar el juego) fue insertar esto "sv_cheats 1" y de ahí desactivar las texturas/mod que le tenía agregadas al tank, con eso me funcionó bastante bien