It looks like the plugin is broken at least since the last Thunar update. Everytime I try to extract an archive by using "Extract here" the plugin claims no supported archive manager is found but xarchiver and file-roller are installed on my box.
This is Fedora-spefic. We no longer use "vendor" for desktop files as per https://fedorahosted.org/fesco/ticket/1077 Now the *.tap files of file-roller and xarchiver need to be adjusted to reflect this change.