The most common solution across the entire trilogy is to cut out the middleman: the game launcher.
: Once inside the game, head to Options > Game and toggle Disable Launcher to "On". Download MAFIA NOT OPENING FIX
: Navigate to your game folder (usually through Steam Library > Manage > Browse Local Files ) and double-click the actual game application (e.g., mafiadefinitiveedition.exe ) rather than the launcher. The most common solution across the entire trilogy
Mafia DE refuses to start (Every Mafia game refuses to start) Download MAFIA NOT OPENING FIX