Could not validate license. Reason: Curl error: couldn't connect to host

During the installation in the validation of license step, the installation would stop because of error
Could not validate license. Reason: Curl error: couldn't connect to host.
This means, that your server was not able to connect to our server located on Internet (url members.qualityunit.com)
Possibly is your server behind any firewall and it is not able to access Internet servers.
Please try to remove this blocking of requests on your server to Internet and it should start to work.