remote: GitLab: API is not accessible

Hi,

We have an on-premises gitlab server with GitLab community edition installed.

When we try to do a git push, it throws "remote: GitLab: API is not accessible To https://domain_name/groupname/repo_name.git ! [remote rejected] branch_name -> branch_name (pre-receive hook declined) error: failed to push some refs to 'https://domain_name/groupname/repo_name.git' " error.

This behavior is for only few repos.

Can someone please share if any solution for this.

GitLab version: GitLab Community Edition 11.7.5 OS version : CentOS 7.5