diff --git a/core/modules/views/src/ViewExecutable.php b/core/modules/views/src/ViewExecutable.php
index db01ad8..204b633 100644
--- a/core/modules/views/src/ViewExecutable.php
+++ b/core/modules/views/src/ViewExecutable.php
@@ -1910,7 +1910,8 @@ public function validate() {
     $this->initDisplay();
     $current_display = $this->current_display;
 
-    foreach ($this->displayHandlers as $id => $display) {
+    $display_handlers = iterator_to_array($this->displayHandlers);
+    foreach ($display_handlers as $id => $display) {
       if (!empty($display)) {
         if (!empty($display->display['deleted'])) {
           continue;