You get this message when the system is behind a firewall and when the security certificates are blocked.
There are two ways to overcome this message and to enable a git pull or git clone.
i) Issue the below command from git bash
$ git config –global http.sslVerify false
ii) Add http block in “gitconfig” file to avoid ssl verification[http] sslVerify = false
sslCAinfo = /bin/curl-ca-bundle.crt