I have 2 nights booked for a comp room at Mirage. I received an email 3 days ago with an upgrade offer, however, when I click on the offer I get this message: "We're sorry, there seems to be some trouble accessing your upgrade offer. Please try again at a later time." I have tried it all 3 days and get the same message every time. I would call but it says it is only valid online. I know I could try for an upgrade at check in, but just wanted to see what it says about the upgrade. Has anyone else encountered this before?