Recently, a new Remnant From The Ashes update was released with fixes for weapons, items, mods, matchmaking and more. Unfortunately, after the update, many players are experiencing several performance issues, crashing and getting error ce-34878-0 while playing the game online.
If you are also facing Remnant From The Ashes error ce-34878-0 issue, here is a couple of fixes you can try. According to the game devs,performance issues are being caused by 4k resolution output. You can fix this issue by changing the PS4 Video Output Settings to 1080p. You can also disable Supersampling Mode in the Video Output Settings. This will also improve the game performance.
Error CE-34878-0 is a general error indicating that the game has crashed. If you receive a CE-34878-0 error, you will need to restart the game. A fix is coming in the future update.