I previously asked this question Senior co-author is jeopardizing two years of work.
I have been trying to address my senior co-author's concerns. However, he is still not happy, and has now started to openly insult me in the group email discussions among all co-authors.
What should I do? My supervisors and other co-authors appear to choose to remain silent. I will be soon applying elsewhere, so I would like to have good recommendation letters. It is becoming difficult to care what happens to the paper, since it would be in preparation anyway while I am applying elsewhere.
Academia is a small world, so I would like to remain on as good terms as possible with everyone, including the difficult co-author.
(PS. I would accept the highest voted answer in the other question but I lost my login)