git 使用问题

今天使用git是发现无法切换分支，报错如下：

git -c diff.mnemonicprefix=false -c core.quotepath=false checkout feature/s_mybills
fatal: Unable to create 'E:/'''/.git/index.lock': File exists.

Another git process seems to be running in this repository, e.g.
an editor opened by 'git commit'. Please make sure all processes
are terminated then try again. If it still fails, a git process
may have crashed in this repository earlier:
remove the file manually to continue.git -c diff