Since February 25, customers have published bug reports and queries on both the Capcom and PlayStation support forums, detailing a bug that is preventing them from playing DLC that had already been purchased via the PlayStation Store.
Specifically, the issue is that pre-ordered versions of Resident Evil Revelations 2 were bundled with special maps for Raid Mode, partly as an incentive to buy the game in advance. For some users, however, these maps remain inaccessible.
Sony sometimes allows players to pre-install games on the PlayStation 4 before their official release date, thereby eliminating download wait times once a game is available to play. But in order to prevent people from playing games early, pre-installed content is "locked" until release day.
It appears that the issue with Resident Evil Revelations 2, however, is that the map packs have no unlock date, leaving them in limbo.
In late March, when the issue dragged into its fifth week, a Sony representative wrote on the support forums that "our store team is aware of the issue. Thanks for the reports."