Deleting the branch ref file did not work for me. Instead, I manually updated the file with the most recent commit from the remote branch.

1. git status -> bad HEAD object
2. git pull -> did not send all necessary objects
3. rm .git/refs/remotes/origin/<name of branch> -> No change
4. echo <most recent commit hash from remote> > .git/refs/remotes/origin/<name of branch>
5. git pull && git reset -> It works!