https://wccftech.com/ps5-bugs-issues-bricked-consoles-external-hdd-rest-mode/

The PlayStation 5 is out in the wild now, and while most people are enjoying the new console, there are also players (on Reddit, ResetEra and elsewhere) reporting a variety of glitches and issues. In some cases, these issues have required factory resets of the PS5 hardware or outright bricked the system. Now, don’t get too worried – these kind of reports happen during pretty much every new console launch. Chances are your PS5 will be just fine. That said, there does seem to be two things that are causing most of the problems, and thankfully, both of them are fairly easily avoided.

The biggest culprit would seem to be external hard drives. While PS5 games can only played off the system’s internal solid-state drive, you can also plug in an external HDD and play PS4 games off that. Unfortunately, the feature currently has issues, with many encountering a “rebuild database” bug. Basically, you try to play a PS4 game, the game or PS5 crashes, and then you start getting “the database has corrupted, it will now rebuild” error messages. In some cases, these can lead to further issues or even the dreaded bricked system.