1. Set up the site (before patch is applied): Install gs: apt-get update && apt-get install ghostscript Create a course. Create 3 students: Student One , Student Two and Student Three . Enrol students to the course with Student role. Crate Assignment activity with Submission types set to File submissions and Annotate PDF enabled in Feedback types . Log in as Student One and submit a submission with an image. Connect to the database. Confirm , that submission conversion is queued: SELECT * FROM mdl_assignfeedback_editpdf_queue; 2. Generate ad-hoc tasks for not yet converted queue items: Apply the patch. Run upgrade script: php admin/cli/upgrade.php Log in as an admin. Access Scheduled tasks admin page. Confirm , that assignfeedback_editpdf\task\convert_submissions doesn't exist anymore. Connect to the database. Confirm , that mdl_assignfeedback_editpdf_queue table doesn't exist anymore. Confirm , that ad-hoc task was created for Student One submission: SELECT * FROM mdl_task_adhoc; Run ad-hoc tasks: php admin/cli/adhoc_task.php --execute Confirm , that \assignfeedback_editpdf\task\convert_submission has been completed successfully. Access grading page for Student One. Confirm , that student submission is displayed. 3. Convert new submissions in cron: Log in as Student Two and submit a submission with an image. Confirm , that ad-hoc task was created: SELECT * FROM mdl_task_adhoc; Run ad-hoc tasks: php admin/cli/adhoc_task.php --execute Log in as Teacher. Access grading page for Student Two. Confirm , that student submission is displayed. 4. Convert new submissions in teacher session: Log in as Student Three and submit a submission with an image. Confirm , that ad-hoc task was created: SELECT * FROM mdl_task_adhoc; Log in as Teacher. Access grading page for Student Three. Confirm , that student submission is displayed. Run ad-hoc tasks: php admin/cli/adhoc_task.php --execute Confirm , that \assignfeedback_editpdf\task\convert_submission has been completed successfully.