For the others out there having the yellow loading box problem, here is the solution.
Because GMS uses IE and http://maps.google.com, you must set this site as a trusted site in your security settings.
1> Open IE go to Tools Menu, then Internet Options
2> Select Security tab, Trused Sites (green tick icon), click Sites button
3> type “http://maps.google.com” (without speech marks) into the ‘Add this website to the zone’ box, then click Add button.
That’s it, should work fine. If google.com maps (it is important it’s maps.google.COM) works in IE browser, then it should work in GMS.