In a course with enrolled students, create an assignment with the following settings: Submission types: Online text Feedback types: Feedback comments and Annotate PDF Comment inline: Yes Attempts reopened: Manually As a student, go to the assignment and some text as a submission. As a teacher go to the "View all submissions" page and choose "Allow another attempt" for this student. Run cron. php admin/cli/cron.php As a student, go to the assignment and choose "Add a new attempt". Confirm that the page loads okay. Verify you don't see an exception: "Exception - Argument 1 passed to core_renderer::user_picture() must be an instance of stdClass, string given, called in [dirroot] /mod/assign/renderer.php".