I saw this Last Week on Tuesday. I think it has to with the Elite Issues. I think that they are have tried link up / sync the Activision Accounts with the Elite account and that must be broken and that could be why you don't see the options.
I think that if you can try the following. Close out all of browser windows. Then just go to www.callofduty.com/mw3. Login In there and not via Elite. Then it might come up.
I can't say for certain, but maybe they are updating their site? Sometimes quirky things like this happen when the site is being maintenanced. Otherwise my only other guess is that maybe you got banned? Can you PM anyone on that site to see if they can make posts? If so ask the person you PM to contact one of the moderators for you to see if they can help.