Hi Mark,
I, too, have hit similar problems when trying to install EasySocial 2.1. I'm attaching screen prints.
install_screen1 shows passthru as disabled, but when you click the "Fix This" prompt, it comes up with a "Page not found" message ( install_screen2 ) for
https://stackideas.com/docs/easysocial/administrators/setup/passthru.
You may wish to consider updating your documentation with the answer you've given Nubuwat.
Thanks for the explanation. I'm on a shared server, so will need to contact my service provider.
Jack