There's a really nasty exploit in the PS4 FW right now that people are taking advantage of to crash and temporarily brick your console (you need to factory reset in order to use your console after it happens) It's caused by people sending images which overflow the consoles memory. Best set your messaging to private so randoms can't do this to you in open lobbies guys n gals. More info here - https://www.reddit.com/r/PS4/comments/9nselm/warning_set_your_messages_to_private/