The Viewer Applet Software can be slow to load on the first time, and so be patient!
Additionally, the ribosome is a MASSIVE MOLECULE, and so loading the molecule will also seem to take an inordinate amount of time after the applet has finished loading.
THIS MAY TAKE SEVERAL MINUTES (ABOUT 4 MINUTES) WITH A HIGH-SPEED CONNECTION.
If the molecule does not show after about 4 minutes following the applet loading, close all browser windows to clear the JAVA memory and retry. This generally fixes all problems, particularly if other molecules did load and you are now trying a different one.
On certain older Macs, we have only seen that the JAVA memory is only sufficient for the 5.5 Å models.
Please do not resize the window until the ribosome molecule is visible.