Change the direction of writing, in Wikipedia
When I right-click on the "Reverse Page Direction" menu, the writing direction does not change, and remains the same, and I have to use an external plugin.
Thanks to the respondents
Hmm, Firefox 56.0 is quite old. Doesn't your Linux distro support a more recent Firefox version?
Verify that you meet the System Requirements (GTK+ and GLib) for the current Firefox release.
Does the "Ctrl+Shift+X" shortcut work in the "Post a reply" text area used in this forum ?