I basically am using the free package I have 1 site called smartair.ml with one subdomain set up as crew.smartair.ml the smartair.ml was working until I added a subdomain here are some screenshots of my directories (click the links to view screenshots)
Please help!
As you can see in the Addon Domain section in your control panel, the directory for smartair.ml is htdocs and not smartair.ml/htdocs. Since smartair.ml is the first domain name of your account, it gets assigned to the main htdocs directory rather than a domain specific folder.
Just create a new folder in the root directory called htdocs and move your website to it. That should fix your website.
Thanks mate so much 
Amazing hosts will def be getting paid soom