When creating new certificates using the "Certificate tool manager" on Moodle 4.0 the following debug notices are displayed when adding a user field (since these fields were removed by MDL-28452 in Moodle 3.11)

[Mon Jul 25 13:24:53.089390 2022] [php:notice] [pid 150523] [client 10.0.6.50:60284] Debugging: Invalid get_string() identifier: 'icq' or component 'moodle'. Perhaps you are missing $string['icq'] = ''; in lang/en/moodle.php? in \n* line 356 of /lib/classes/string_manager_standard.php: call to debugging()\n* line 7361 of /lib/moodlelib.php: call to core_string_manager_standard->get_string()\n* line 665 of /user/classes/fields.php: call to get_string()\n* line 49 of /admin/tool/certificate/element/userfield/classes/element.php: call to core_user\\fields::get_display_name()\n* line 62 of /admin/tool/certificate/element/userfield/classes/element.php: call to certificateelement_userfield\\element->certificateelement_userfield\\\\

{closure}()\n* line 102 of /admin/tool/certificate/classes/edit_element_form.php: call to certificateelement_userfield\\element->render_form_elements()\n* line 214 of /lib/formslib.php: call to tool_certificate\\edit_element_form->definition()\n* line 69 of /admin/tool/certificate/classes/modal_form.php: call to moodleform->{}construct()\n* line 74 of /admin/tool/certificate/classes/external/modal_form.php: call to tool_certificate\\modal_form->{_}_construct()\n* line 261 of /lib/externallib.php: call to tool_certificate\\external\\modal_form::execute()\n* line 81 of /lib/ajax/service.php: call to external_api::call_external_function()\n, referer: https://moodleURL/admin/tool/certificate/template.php?id=2

[Mon Jul 25 13:24:53.089440 2022] [php:notice] [pid 150523] [client 10.0.6.50:60284] Debugging: Invalid get_string() identifier: 'skype' or component 'moodle'. Perhaps you are missing $string['skype'] = ''; in lang/en/moodle.php? in \n* line 356 of /lib/classes/string_manager_standard.php: call to debugging()\n* line 7361 of /lib/moodlelib.php: call to core_string_manager_standard->get_string()\n* line 665 of /user/classes/fields.php: call to get_string()\n* line 49 of /admin/tool/certificate/element/userfield/classes/element.php: call to core_user\\fields::get_display_name()\n* line 63 of /admin/tool/certificate/element/userfield/classes/element.php: call to certificateelement_userfield\\element->certificateelement_userfield\\\\{closure}

()\n* line 102 of /admin/tool/certificate/classes/edit_element_form.php: call to certificateelement_userfield\\element->render_form_elements()\n* line 214 of /lib/formslib.php: call to tool_certificate\\edit_element_form->definition()\n* line 69 of /admin/tool/certificate/classes/modal_form.php: call to moodleform->{}construct()\n* line 74 of /admin/tool/certificate/classes/external/modal_form.php: call to tool_certificate\\modal_form->{_}_construct()\n* line 261 of /lib/externallib.php: call to tool_certificate\\external\\modal_form::execute()\n* line 81 of /lib/ajax/service.php: call to external_api::call_external_function()\n, referer: https://moodleURL/admin/tool/certificate/template.php?id=2

[Mon Jul 25 13:24:53.089473 2022] [php:notice] [pid 150523] [client 10.0.6.50:60284] Debugging: Invalid get_string() identifier: 'aim' or component 'moodle'. Perhaps you are missing $string['aim'] = ''; in lang/en/moodle.php? in \n* line 356 of /lib/classes/string_manager_standard.php: call to debugging()\n* line 7361 of /lib/moodlelib.php: call to core_string_manager_standard->get_string()\n* line 665 of /user/classes/fields.php: call to get_string()\n* line 49 of /admin/tool/certificate/element/userfield/classes/element.php: call to core_user\\fields::get_display_name()\n* line 64 of /admin/tool/certificate/element/userfield/classes/element.php: call to certificateelement_userfield\\element->certificateelement_userfield\\\\

{closure}()\n* line 102 of /admin/tool/certificate/classes/edit_element_form.php: call to certificateelement_userfield\\element->render_form_elements()\n* line 214 of /lib/formslib.php: call to tool_certificate\\edit_element_form->definition()\n* line 69 of /admin/tool/certificate/classes/modal_form.php: call to moodleform->{}construct()\n* line 74 of /admin/tool/certificate/classes/external/modal_form.php: call to tool_certificate\\modal_form->{_}_construct()\n* line 261 of /lib/externallib.php: call to tool_certificate\\external\\modal_form::execute()\n* line 81 of /lib/ajax/service.php: call to external_api::call_external_function()\n, referer: https://moodleURL/admin/tool/certificate/template.php?id=2

[Mon Jul 25 13:24:53.089492 2022] [php:notice] [pid 150523] [client 10.0.6.50:60284] Debugging: Invalid get_string() identifier: 'yahoo' or component 'moodle'. Perhaps you are missing $string['yahoo'] = ''; in lang/en/moodle.php? in \n* line 356 of /lib/classes/string_manager_standard.php: call to debugging()\n* line 7361 of /lib/moodlelib.php: call to core_string_manager_standard->get_string()\n* line 665 of /user/classes/fields.php: call to get_string()\n* line 49 of /admin/tool/certificate/element/userfield/classes/element.php: call to core_user\\fields::get_display_name()\n* line 65 of /admin/tool/certificate/element/userfield/classes/element.php: call to certificateelement_userfield\\element->certificateelement_userfield\\\\{closure}

()\n* line 102 of /admin/tool/certificate/classes/edit_element_form.php: call to certificateelement_userfield\\element->render_form_elements()\n* line 214 of /lib/formslib.php: call to tool_certificate\\edit_element_form->definition()\n* line 69 of /admin/tool/certificate/classes/modal_form.php: call to moodleform->{}construct()\n* line 74 of /admin/tool/certificate/classes/external/modal_form.php: call to tool_certificate\\modal_form->{_}_construct()\n* line 261 of /lib/externallib.php: call to tool_certificate\\external\\modal_form::execute()\n* line 81 of /lib/ajax/service.php: call to external_api::call_external_function()\n, referer: https://moodleURLadmin/tool/certificate/template.php?id=2

[Mon Jul 25 13:24:53.089521 2022] [php:notice] [pid 150523] [client 10.0.6.50:60284] Debugging: Invalid get_string() identifier: 'msn' or component 'moodle'. Perhaps you are missing $string['msn'] = ''; in lang/en/moodle.php? in \n* line 356 of /lib/classes/string_manager_standard.php: call to debugging()\n* line 7361 of /lib/moodlelib.php: call to core_string_manager_standard->get_string()\n* line 665 of /user/classes/fields.php: call to get_string()\n* line 49 of /admin/tool/certificate/element/userfield/classes/element.php: call to core_user\\fields::get_display_name()\n* line 66 of /admin/tool/certificate/element/userfield/classes/element.php: call to certificateelement_userfield\\element->certificateelement_userfield\\\\

{closure}

()\n* line 102 of /admin/tool/certificate/classes/edit_element_form.php: call to certificateelement_userfield\\element->render_form_elements()\n* line 214 of /lib/formslib.php: call to tool_certificate\\edit_element_form->definition()\n* line 69 of /admin/tool/certificate/classes/modal_form.php: call to moodleform->{}construct()\n* line 74 of /admin/tool/certificate/classes/external/modal_form.php: call to tool_certificate\\modal_form->{_}_construct()\n* line 261 of /lib/externallib.php: call to tool_certificate\\external\\modal_form::execute()\n* line 81 of /lib/ajax/service.php: call to external_api::call_external_function()\n, referer: https://moodleURL/admin/tool/certificate/template.php?id=2