Custom link provider test Note: This is also covered by behat and unit tests. Enable the communication subsystem from site administration > Development > Experimental settings. Create a new course and enrol a teacher and student into it. Visit the course as the teacher and navigate to More > Communication. Select Custom link as the provider. Set the custom link URL to https://matrix.to/#/#moodledev:moodle.com Press save changes . CONFIRM you see the blue communication button at the bottom right of the screen. Click the communication button and CONFIRM a new tab opens which loads the "Moodle Dev chat" Matrix link, then close that tab. Run adhoc tasks using the following in the command line in your site's root directory: php admin/cli/adhoc_task.php Refresh the course homepage. CONFIRM the communication button still exists and CONFIRM clicking it loads the same page as in step 8. Return to More > Communication, switch the provider to "None" and save. Re-enable the Custom link provider and repeat steps 5-11, CONFIRMING you see the same outcome. Communication button fixes On the course homepage, expand and collapse the blocks drawer on the right of the page and CONFIRM that the communication button remains directly above the footer button (ie it should move inwards when the drawer is expanded and out when it is collapsed). Save the attached openertest.html file into your web root (ie localhost). In the course, set the custom link URL to http://localhost/openertest.html (adjust if you put it somewhere else in your web server). Once that custom link provider change is saved, click on the communication button. CONFIRM that you see "test 1 pass " and "test 2 pass " when openertest.html loads, then close the tab. When you return to the tab you originally came from, CONFIRM it still shows the course homepage, and has not been redirected to DuckDuckGo.