Somehow you have a single media record marked as the replace for 2 media records, which is causing the error you’ve got there.
To fix it the record you can run:
UPDATE `media` SET editedmediaid = null WHERE mediaid = 92;
The delete should be successful after that.
I am not sure how it got into this condition - that file does have a lot of revisions that previously worked OK (and i’ve deleted back several revisions to ensure that works).
1.8 has a new mode which will “delete old revision” when you do a replace - I think that this will streamline your library going forwards, so that you only ever have the active copy in the library - the others are removed as you go.
Please can you run the above SQL and let me know if that solves your issue?
Thanks