Getting '__path__' not set error while opening index.php

Curious, Did you follow the setup guide that includes the rewrite rules? Check your apache / nginx configuration

Just to be sure i reinstalled the whole thing in a new machine(Centos 7), but was still getting this issue. I switched to ubuntu and it works fine for me. I followed this one as well but still din't make it to work. https://blogs.gnome.org/aklapper/2014/11/10/phabricator-on-fedora-20/

Maybe T4947: SELinux / AppArmor ruin everything all the time?

@chad Could be. I wasted a whole day on this. Anyways i moved to ubuntu now and it seems to be working pretty well there.