Some users are reporting that after upgrading their PlayStation 4 systems to version 2.50, they were forced to redownload Bloodborne's Day One update again for reasons only Sony can fathom.
In doing so, the update corrupted users' save files, preventing them from continuing their previously existing games. Any attempt to hit "continue" or "load game" would result in a pop-up message saying that an update was in progress and that the game was unable to load. Given that there's no update in progress, users could only surmise that they lost their saves.
Fortunately, there's a simple workaround for fixing these corrupted saves: simply start up Bloodborne and start a "new game". Once you're in control of your character, go back out to the main menu and you should be able to choose "load game" and reload your original save file.
That's it. Happy gaming!