reverted:
--- b/core/modules/system/tests/src/Functional/Form/ValidationTest.php
+++ a/core/modules/system/tests/src/Functional/Form/ValidationTest.php
@@ -240,11 +240,11 @@
     foreach (Element::children($form) as $key) {
       if (isset($form[$key]['#required_error'])) {
         $this->assertNoText($form[$key]['#title'] . ' field is required.');
+        $this->assertNoText($form[$key]['#required_error']);
-        $this->assertNoText($form[$key]['#required_error']->render());
       }
       elseif (isset($form[$key]['#form_test_required_error'])) {
         $this->assertNoText($form[$key]['#title'] . ' field is required.');
+        $this->assertNoText($form[$key]['#form_test_required_error']);
-        $this->assertNoText($form[$key]['#form_test_required_error']->render());
       }
     }
     $this->assertNoText('An illegal choice has been detected. Please contact the site administrator.');
diff -u b/core/modules/system/tests/src/Functional/Module/UninstallTest.php b/core/modules/system/tests/src/Functional/Module/UninstallTest.php
--- b/core/modules/system/tests/src/Functional/Module/UninstallTest.php
+++ b/core/modules/system/tests/src/Functional/Module/UninstallTest.php
@@ -86,7 +86,7 @@
     $edit = [];
     $edit['uninstall[module_test]'] = TRUE;
     $this->drupalPostForm('admin/modules/uninstall', $edit, t('Uninstall'));
-    $this->assertNoText(\Drupal::translation()->translate('Configuration deletions')->render(), 'No configuration deletions listed on the module install confirmation page.');
+    $this->assertNoText('Configuration deletions', 'No configuration deletions listed on the module install confirmation page.');
     $this->assertText(\Drupal::translation()->translate('Configuration updates'), 'Configuration updates listed on the module install confirmation page.');
     $this->assertText($node_type->label());
     $this->drupalPostForm(NULL, [], t('Uninstall'));
@@ -99,7 +99,7 @@
     $edit['uninstall[node]'] = TRUE;
     $this->drupalPostForm('admin/modules/uninstall', $edit, t('Uninstall'));
     $this->assertText(\Drupal::translation()->translate('Configuration deletions'), 'Configuration deletions listed on the module install confirmation page.');
-    $this->assertNoText(\Drupal::translation()->translate('Configuration updates')->render(), 'No configuration updates listed on the module install confirmation page.');
+    $this->assertNoText('Configuration updates', 'No configuration updates listed on the module install confirmation page.');
 
     $entity_types = [];
     foreach ($node_dependencies as $entity) {
reverted:
--- b/core/modules/tracker/tests/src/Functional/TrackerNodeAccessTest.php
+++ a/core/modules/tracker/tests/src/Functional/TrackerNodeAccessTest.php
@@ -59,7 +59,7 @@
 
     // Create some nodes.
     $private_node = $this->drupalCreateNode([
+      'title' => t('Private node test'),
-      'title' => 'Private node test',
       'private' => TRUE,
     ]);
     $public_node = $this->drupalCreateNode([
reverted:
--- b/core/tests/Drupal/FunctionalTests/AssertLegacyTrait.php
+++ a/core/tests/Drupal/FunctionalTests/AssertLegacyTrait.php
@@ -113,9 +113,6 @@
    */
   protected function assertNoText($text) {
     @trigger_error('AssertLegacyTrait::assertNoText() is deprecated in drupal:8.2.0 and is removed from drupal:10.0.0. Use $this->assertSession()->responseNotContains() or $this->assertSession()->pageTextNotContains() instead. See https://www.drupal.org/node/3129738', E_USER_DEPRECATED);
-    if (is_object($text)) {
-      @trigger_error('Passing MarkupInterface objects to AssertLegacyTrait::assertNoText() is deprecated in drupal:9.1.0 and is removed from drupal:10.0.0. Pass plain strings instead. See https://www.drupal.org/node/xxxxxxx', E_USER_DEPRECATED);
-    }
     // Cast MarkupInterface to string.
     $text = (string) $text;