Citing the usual stability fixes, PlayStation 4 firmware 2.57 was released this morning. However, rather than being a mandatory update that blocks you from accessing the PlayStation Network until it is installed, this update is entirely optional.
Unfortunately, the update does not fix a disc reading bug introduced with firmware 2.55 which we reported on a fortnight ago, whereby waking the console up with by ejecting a disc would mean that the PlayStation 4 would then fail to recognise discs that are subsequently inserted, unless you restarted the console entirely.
Source: PlayStation
