[Never mind. I just discovered I should use File | Open.. instead] I have a lot of sketches, way too many to show in the File\sketchbook dropdown because it does not have scrolling capability. Why can it not be made to scroll?! Bring it up into the 21st century or even the 20th century would be nice... I have put many into folders but I just have too many categories. The folders, themselves, would often only contain one sketch and the folders would be so numerous they could not all be displayed.
without any info on your system and version of the os this is useless information
scrolling works fine on my old mac running os 10.5.8
using the scroll wheel on the mouse, the up/down arrows, even the page up and down buttons
i have way too many sketches too - as i tend to save every experiment with the examples
most of the time I just open the folder manually and double click the file to open it