Quote - um why not use Acrobat PDF instead, see if it's the pdf reader to blame? :)

I'm on MacOS and the Apercu program is the PDF reader that is bundled with the system.
I never feel the need to install Acrobat.
I'm sure Apercu is not the problem because Shade (and many other programs) has the same help menu that opens a PDF and all is fine with Apercu.

Actually, it seems that Vue wakes up upon several minutes after showing the rainbow wheel ...