Issue #3295818: TypeError: count(): Argument #1 ($value) must be of type Countable|array, null given

src/Form/EntityEmbedDialog.php

@@ -593,7 +593,7 @@ class EntityEmbedDialog extends FormBase {
    */
   public function validateSelectStep(array $form, FormStateInterface $form_state) {
     if ($form_state->hasValue(['entity_browser', 'entities'])) {
-      if (count($form_state->getValue(['entity_browser', 'entities'])) > 0) {
+      if (!empty($form_state->getValue(['entity_browser', 'entities']))) {
         $id = $form_state->getValue(['entity_browser', 'entities', 0])->id();
       }
       $element = $form['entity_browser'];