https://www.gamespot.com/articles/destiny-2-ps4-pro-crash-errors-continue-sony-and-b/1100-6453184/

Update: It seems that the issue involving crashes on PS4 Pro have still not been fully resolved. Bungie recently passed along a message from Sony's support account on Twitter, which states, "We're aware that some Destiny 2 users have seen crash issues on PS4 Pro. We and Bungie are working to resolve, thanks for your patience." There's no word yet on when this might be fixed, but if you haven't tried disabling HDCP (as outlined below), it could be worth a try. The original story follows.

After many PlayStation 4 players found themselves unable to play Destiny 2 due to server errors, today has brought with it a new problem. A number of players have reported a PS4 crash error that's begun popping up, and Bungie says it's aware, though it doesn't yet have a fix.