Broken branch in git, fatal: your current branch appears to be broken

Question

Here is my case:

• I was working on one branch.
• Pushed new commits to the remote.
• Switched back to the master branch.

But suddenly

Answer 1

I meet similar issue on Windows 7. In my case，the current branch file (refer by ./git/HEAD) under \.git\refs\heads was broken.

I found the hash code of broken current branch on .git\logs\refs\heads with same branch name.

And I fixed the issue by opening that file (.git\logs\refs\heads\xxx) via notepad and copy the 4th number (the hash code) to (.git\refs\heads\xxx)