Hi,
Course administration has been removed from the dashboard in the updated versions of Moodle.
However there are just a few steps you need to follow to get 'Course Administration' block back for your Moodle courses.
1) Login to your Moodle website as Admin.
2) Turn editing on / click on "Customize this page" option at the top-right of the main page.
3) Go to any course or My courses page and click on "add block" option present in the dashboard.
4) Click on the "Administration" option.
5) Doing that will add the requested "Course Administration" block on the right hand side of the Course page. (see image)
[P.S : These steps are valid for all themes, be it Boost or RemUI, I tested it in multiple themes, worked for all of them.]