BioShock 2 map pack problems
Issues with the Rapture Metro map pack for BioShock 2 were intentionally designed explains publisher 2K Games, as it responds to community complaints about not being able to play maps purchased with the expansion.
Eurogamer reports that the maps included in the Rapture Metro download can only be used with other players who have purchased the expansion.
2K's Elizabeth Tobey explains that this was intentional in order to ensure that players without the map pack could still play with those who did download it. Her suggestion as described by Rapture Archives is to create a private match to filter in players that have the Rapture Metro maps.
It's a messy approach to the issue, yet the desire to maintain a level playing field for those who haven't purchased the optional map pack is admirable.