I have been getting this message quite a few times and now I am having classmates tell me they are getting the same thing with a grey box saying after 5 minutes press F5. What is causing this? How can I clear this out so people can access the page. We just had a large reunion and people are trying to get to the site to see photos and getting this message.

Tell them to refresh/reload the page. This usually clears the problem. It is happening more frequently because of code changes for the Facebook App called "ClassConnection".