The official way to download and play Cambalache 2 is through the Steam Workshop. If you are prompted for a password, it is highly likely you are looking at an older, external version, or a site that is not affiliated with the creator.
If the passwords fail to trigger an event, players often suggest checking for mod conflicts. Disabling other custom campaigns in the L4D2 Add-ons menu
: You can find and subscribe to the map on the Steam Workshop, where it has garnered hundreds of thousands of visitors and high ratings. Useful Console Commands