I just got quite a strange problem: I spotted this release https://musicbrainz.org/release/3be24d19-50f6-4ed3-b6a6-747f4c8d65dc where the release artists are in the title and not in the release artist category. So naturally, I changed the title and transferred the artists from the release title into the release artist category and did the same for the release group for good measure. However, one of these artists is a new artist, that I had to create for that: ‘Chor der Staatsoper München’ . However, if an artist doesn’t get a relation in the few days after it got created, it gets deleted. Where the problem is is that to apply this change in release title and artist, I have to wait a few days to be open for critics and votes, and then I got this: https://musicbrainz.org/edit/54609863 . So it seems that since nothing has been linked to the new artist, it has been deleted and therefore the edit failed, even though the linking was pending.
I am conscious that I could have handled this better (by looking up a relation for this artist, in this case its main concert venue seems rather obvious) but it still seems to me that the timer for applying changes and the timer for deleting artists should be tuned a bit better (or artists that have open edits do not get deleted) to avoid this kind of frankly ridiculous problem.
This is a bug as ModBot is supposed to check artist for open edits before deletion.
I forwarded your bug report to ticket MBS-9781.