Cannot view webpage/blog on the web

I have four webpage/blogs hosted with InMotion Hosting. The primary domain has three subdomains for three of the sites. The subdomains are functioning perfectly.

I keep having a problem with the primary domain no being visible on the web. I am able to get into the dashboard and all the files are there and look fine. One day it works, the next day it doesn’t. The site is a test site called “whatyoushouldknow.us”. Can anyone tell me why the browser cannot view this site?

Yesterday it was not visible in Chrome, but was visible in Firefox. Today I cannot view it at all.