Log In Error - 'We could not reach the server, Please try again'. Why is this?

If you receive the following message when accessing www.timesheetz.net

The problem is due to the security policy on the PC which is blocking access to this URL https://s3.amazonaws.com/assets.auth0.com/client/WHsXXILzxnVvNG96YMcxjsSq1AE5HQHf.js?t1423763110563

Please can you ask your IT security to unblock the following URL.. https://s3.amazonaws.com/assets.auth0.com/ 

If this is not possible the Timesheet system is accessible on mobile devices .