To render a flipbook, you must select a node for viewing. Click on the left side of the node, which should make it appear in the Viewer. When you can see an image in the Viewer, you can render a flipbook.
If that doesn't work, look in the Shake application folder, located at:
You should see the applications shkv and shkqtv in the folder with shake.
If not, there is a problem with your installation.