Not sure if anyone else has run into this issue with the docked menu tree not being visible. I have the latest Ignition Edge version (8.1.26) and imported the Perspective Menu Navigation Project from Exchange.
Below is a snippet of the Perspective Session after importing the project from Exchange (Docked Menu Tree not visible):
I searched high and low trying to solve this and decided to remove the following from stylesheet.css:
width: auto !important;
Once that was removed, the menu tree was visible:
I am posting this just in case it helps someone else in the future and to confirm my action was suitable.