There is no error code.
[media]Just want to add that our year (ish) old world keeps doing this. Each time we go back to the most recent back up and it works fine for a couple of days, but then refuses to load again, so need to go back to the same back up.
At this point, we've mined out the same 50 x 2 x 50 block area three times and we're pretty close to just giving up on it entirely.
We've been having this issue on our PS4 since the 1.17 update and haven't been able to get back into the world since.
Since we had this issue after 1.16, but fixed it with an uninstall reinstall, then had it again at some point and fixed it by going back in our saves, we tried both of those. Neither seems to be working this time, though.