Fastpages fails to deploy updates

After pushing new commits, the deployment step fails when running the action:

I tried upgrading fastpages, but also got an error:

Any ideas on how I could fix it and get back to blogging again? Let me know if there is any extra information that I should provide.

I had similar problem, I was crashing on “git credentials failed”. I checked automatic updates but found easy fix - back up all your posts, delete repository and create it from scratch. Then paste old posts and blog will be up and running

This worked for me, but I had no comments from the Utterances app on my blog. This solution would not be viable for someone who had comments since all of them would be lost if they were just to delete the repository.