Pull mirroring failed with comm-graph.lock file error

This is the error I am receiving:

2:Fetching remote upstream failed: warning: unable to find all commit-graph files warning: unable to find all commit-graph files fatal: Unable to create '/var/opt/gitlab/git-data/repositories/@hashed/b0/c0/b0c01053daf84ec4dc166b6ba53a64bd3591373d74c88b37ba0eb2c491b533ca.git/./objects/info/commit-graphs/commit-graph-chain.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.

Any help is appreciated. thanks