Testing This issue can be tested by anywhere that the TinyMCE editor is available to that user. The below is a single test case to confirm functionality. Log into Moodle as a user that can create courses (admin is easy) Click the create course button if there are no courses or select "new course" from the context menu On the course creation page scroll to the "Course summary" field/ Verify that the fullscreen button appears in the TinyMCE toolbar (see attached screenshot) Verify that clicking the fullscreen button makes the editor enter fullscreen mode Verify clicking the fullscreen button while in fullscreen mode returns the editor to its regular "windowed" mode