For some time, Fortnite has had a habit of closing after a few minutes of play, sometimes as early as the first game and sometimes after 2/3. Now this extends to Warzone too.
The error messages are no help to be honest, no error codes, nothing. I suspect it might be the graphics card, but I don’t know how to confirm that either. I have an Nvidia GeForce RTX 2070 Super.
Edit: Problem solved, thanks to @pezmaker@sh.itjust.works, it was the RAM, twice already that Amazon delivers me a defective one. I’ve put the old one back in and no more problems.
So the games are just closing? No blue/black screen, no system crashes? Did you scan your SSD for smart errors? I would try rolling back to a different Graphics driver. I assume you are on Windows?