PS4 Slim crashes in the tower seem to be pretty common. European PS4 Slims in particular for some reason. Usually on the stairs heading down to the Vanguard. I haven't seen any specific fixes except that it may be an issue with overheating or with the VRAM. Pressing Sony is your best option. The only other option I've read about was disabling subtitles (even when there aren't any present during a crash).