I have two separate MODx installs in two separate servers and have recently seen same issue. When you click on some resources in the MODx manager then new page loads as it should but just blank area in the right main area where should be all the editable areas to edit the content of the resource: http://screencast.com/t/RiQnGZxjd
MODX Revolution 2.4.2
With something like this you can usually get to the bottom of the issue by: