Bloodborne Cusa00900 Work May 2026

Fear the old firmware.

“When you get CUSA00900,” one YouTuber theorized, “you aren’t losing progress. You’re experiencing what Yharnam feels like to an Amygdala . Time isn’t linear. The error is a glimpse of the nightmare’s true architecture.”

But not gone.

“Welcome home, good hunter.” To this day, no official explanation has been issued for why the error clustered around the DLC’s most emotionally punishing bosses. But if you listen closely—past the whir of your PS4’s fan, past the login chime—some say you can still hear the faint sound of a tiny, corrupted save file refusing to let go.

But that’s the boring truth. The interesting truth is what happened when players started digging. In early 2022, a Reddit user posted: “CUSA00900 popped up right as I entered the Orphan of Kos arena. Then my save rolled back 6 hours.”