I believe this to be a problem with the restrictions my office has placed on our Internet access, because we had access and then lost it, and I can still access from home, but perhaps someone can point me in the right direction. Our large department has no IT staff familiar with GIS so we are on our own here trying to explain what might be wrong!
I can create a map, and see my groups and my content. But if I try to 'view item details' (by clicking on the map title in the list on my content) I just get a blank window. So I cannot go in and make any changes to the map or to the description, etc. I can view the map from the Group page, but not the details, or the 'more details' from the webmap page.