All "administration pages" in English and admin menu always LTR? I added a RTL language translation file (e.g. Arabic, Persian, Farsi) to my Drupal 8 site. I want all the administration menus to always be in English and LTR. On the other hand, I want the front-end pages of my site to be in another language (e.g. Persian, Farsi).

I did the following.


I enabled the Language module, and set up one additional language. Installation was done in English; I added Persian.


I configured the administration language using the following settings.


/admin/config/regional/language/detection
Account administration pages: enabled



Admin >> Edit Profile >> Edit  




This works properly for all the administration pages. Those are in English and LTR except the front page, user/1/, and admin/structure/block/demo/[theme name] where the administration menu is in Persian and RTL.
After you change default site language to Farsi, and admin pages language to English, go to your user:admin page and change the admin's language to English as well to bring it in accordance with the management backend language (English).

Maybe flushing of cache will be needed; In any case if it didn't work then it's a bug and should be reported at Drupal.org ...