First of all thanks for your good work and the helpful extension!
I have a strange thing going on: On one of my wikis the extension works fine, on the other it doesn't generate any output. I don't see any error messages in the console nor in php_errors.log. On my test install with $wgShowExceptionDetails = true; $wgShowDBErrorBacktrace = true;
there is no error either.
Both the working and the not working wiki run with MW 1.35.7 and PageAuthors 1.4 (f63a4b4). The two wikis are different in terms of installed extensions and different versions (for example SMW). Could another extension interfere with PageAuthors?
Maybe you have another hint that is causing the issue?