Issue #3103010 by AndrewsizZ, No Sssweat, jungle, Lendude, jshimota01: Machine...

Issue #3103010 by AndrewsizZ, No Sssweat, jungle, Lendude, jshimota01: Machine Name needs further clarification

(cherry picked from commit 0e336272)

core/modules/views/src/Plugin/views/display/DisplayPluginBase.php

@@ -1868,7 +1868,7 @@ public function validateOptionsForm(&$form, FormStateInterface $form_state) {
       case 'display_id':
         if ($form_state->getValue('display_id')) {
           if (preg_match('/[^a-z0-9_]/', $form_state->getValue('display_id'))) {
-            $form_state->setError($form['display_id'], $this->t('Display name must be letters, numbers, or underscores only.'));
+            $form_state->setError($form['display_id'], $this->t('Display machine name must contain only lowercase letters, numbers, or underscores.'));
           }
 
           foreach ($this->view->displayHandlers as $id => $display) {

core/modules/views_ui/tests/src/Functional/ViewEditTest.php

@@ -77,7 +77,7 @@ public function testOtherOptions() {
 
     // Test the form validation with invalid IDs.
     $machine_name_edit_url = 'admin/structure/views/nojs/display/test_view/test_1/display_id';
-    $error_text = t('Display name must be letters, numbers, or underscores only.');
+    $error_text = t('Display machine name must contain only lowercase letters, numbers, or underscores.');
 
     // Test that potential invalid display ID requests are detected
     try {