diff -u b/core/modules/text/src/Plugin/Field/FieldType/TextItemBase.php b/core/modules/text/src/Plugin/Field/FieldType/TextItemBase.php
--- b/core/modules/text/src/Plugin/Field/FieldType/TextItemBase.php
+++ b/core/modules/text/src/Plugin/Field/FieldType/TextItemBase.php
@@ -49,8 +49,10 @@
    */
   public function isEmpty() {
     $value = $this->get('value')->getValue();
-    $format = $this->get('format')->getValue();
-
+    $format = NULL;
+    if (isset($this->properties['format'])) {
+      $format = $this->get('format')->getValue();
+    }
     return ($value === NULL || $value === '') && ($format === NULL || $format === '');
   }