Git and nasty “error: cannot lock existing info/refs fatal”

Question

After cloning from remote git repository (at bettercodes) I made some changes, commited and tried to push:

git push origin master

Errors

Answer 1

In my case after getting this message I did the checkout command and was given this message:

Your branch is based on 'origin/myBranch', but the upstream is gone.
  (use "git branch --unset-upstream" to fixup)

After running this command I was back to normal.