> My video generator tab is now missing from the effects window
There is no window called "Effects". The Browser window has a tab called Effects, but theoretically speaking it should be impossible to delete the Video Generators folder from this tab.
The fastest way to access those items is by using the button labelled with an 'A' in a filmstrip, lower right corner of the Viewer window. A nice quick way to get there is by pressing CONTROL-X to call up a template for a title. That reveals the Video Generator button.
Did you recently delete anything from your system folder?