Warning:Undefined array key 0

file_view_access.module

@@ -62,8 +62,8 @@ function file_view_access_field_widget_single_element_form_alter(&$element, Form
  * Custom function after process.
  */
 function file_view_access_field_widget_form_process(&$element, FormStateInterface $form_state, $context) {
-  $fid = $element['fids']['#value'][0];
-  if (is_numeric($fid)) {
+  if (isset($element['fids']['#value'][0]) && is_numeric($element['fids']['#value'][0])) {
+    $fid = $element['fids']['#value'][0];
     $file = $element['#files'][$fid];
     // Get default values.
     $view_access = $file->get('view_access')->value;
@@ -81,6 +81,7 @@ function file_view_access_field_widget_form_process(&$element, FormStateInterfac
   return $element;
 }
 
+
 /**
  * Custom function for handle the Ajax request.
  */