Did you remember to call setType() for 'externalurl'? Defaulting to PARAM_RAW cleaning.

line 1289 of /lib/formslib.php: call to debugging()

line 281 of /lib/formslib.php: call to moodleform->detectMissingSetType()

line 202 of /lib/formslib.php: call to moodleform->_process_submission()

line 3032 of /mod/assign/locallib.php: call to moodleform->moodleform()

line 473 of /mod/assign/locallib.php: call to assign->view_edit_submission_page()

line 53 of /mod/assign/view.php: call to assign->view()