Issue #2571943 by pwolanin, nevergone: Remove !placeholder in file.module

core/modules/file/file.module

@@ -1182,7 +1182,7 @@ function file_managed_file_save_upload($element, FormStateInterface $form_state)
   if ($files_uploaded) {
     if (!$files = file_save_upload($upload_name, $element['#upload_validators'], $destination)) {
       \Drupal::logger('file')->notice('The file upload failed. %upload', array('%upload' => $upload_name));
-      $form_state->setError($element, t('Files in the !name field were unable to be uploaded.', array('!name' => $element['#title'])));
+      $form_state->setError($element, t('Files in the @name field were unable to be uploaded.', array('@name' => $element['#title'])));
       return array();
     }
 

core/modules/file/file.views.inc

@@ -24,7 +24,7 @@ function file_field_views_data(FieldStorageConfigInterface $field_storage) {
       'base' => 'file_managed',
       'entity type' => 'file',
       'base field' => 'fid',
-      'label' => t('file from !field_name', array('!field_name' => $field_storage->getName())),
+      'label' => t('file from @field_name', array('@field_name' => $field_storage->getName())),
     );
   }
 

core/modules/file/src/Plugin/Field/FieldType/FileItem.php

@@ -249,7 +249,7 @@ public static function validateExtensions($element, FormStateInterface $form_sta
    */
   public static function validateMaxFilesize($element, FormStateInterface $form_state) {
     if (!empty($element['#value']) && !is_numeric(Bytes::toInt($element['#value']))) {
-      $form_state->setError($element, t('The "!name" option must contain a valid value. You may either leave the text field empty or enter a string like "512" (bytes), "80 KB" (kilobytes) or "50 MB" (megabytes).', array('!name' => t($element['title']))));
+      $form_state->setError($element, t('The "@name" option must contain a valid value. You may either leave the text field empty or enter a string like "512" (bytes), "80 KB" (kilobytes) or "50 MB" (megabytes).', array('@name' => $element['title'])));
     }
   }