Found it!
Posted: Thu Jul 30, 2020 4:44 pm
I still rely heavily on the Bookends User Guide and as of v13.4.3 I could no longer reach it via the Help menu: "Can't find “Bookends User Guide.pdf” in the Bookends.app package." But checking the package, I found a file called "mbine" which turns out to be the Guide:" file:///Applications/Bookends.app/Contents/Resources/Support%20Files/Documentation/mbine.pdf". But renaming it in place doesn't restore the link. Anything else I can try? (Besides just moving it to a convenient location). Or just wait for 13.4.4