We couldn't get to Office 365 from your on-premises environment using single sign-on. TCP ports 80 and 443 have to be open ...

We couldn't get to Office 365 from your on-premises environment using single sign-on. TCP ports 80 and 443 have to be open on your firewall for single sign-on to work.  Click on the link 'get help fixing this issue' in the actions pane located on the right side of the screen for assistance.