If your students are reporting that they cannot see your course, it may still be in a hidden state. You must change the "Visible" setting (under the course settings) from "hide" to "show."
1) From within your course, click on "Edit settings," under the Administration block.
2) On the Edit course settings page, under the General category, look for and change the "Visible" setting.
3) Save your changes.
This visibility setting of a course determines whether it appears in the list of courses or not. If a course is "hidden" it appears only to users who are enrolled as Teachers in that course, as well as Moodle administrators. Students or other "Teachers" will not see the course listed anywhere.
To tell if your course is currently hidden or visible to students (with the Essential theme) hover over the "My Courses" drop-down menu. Hidden courses will appear with a grey eye icon and grey font. Visible courses will appear with a graduation cap and coloured text. If you have many courses, you may have to scroll to find the course you are looking for.
If you're using Moodle's built-in "Clean" theme, then you can tell by looking at the breadcrumbs at the top of your course page. The part of the breadcrumb showing your course name will be grey if it's hidden and coloured if it's visible.