diff -u b/modules/ctools_block/src/Plugin/Deriver/EntityFieldDeriver.php b/modules/ctools_block/src/Plugin/Deriver/EntityFieldDeriver.php
--- b/modules/ctools_block/src/Plugin/Deriver/EntityFieldDeriver.php
+++ b/modules/ctools_block/src/Plugin/Deriver/EntityFieldDeriver.php
@@ -34,6 +34,13 @@
           // We take the field label used on the first bundle.
           $first_bundle = reset($field_info['bundles']);
           $bundle_field_definitions = $this->entityManager->getFieldDefinitions($entity_type_id, $first_bundle);
+
+          // The field storage config may exist, but it's possible that no
+          // fields are actually using it. If that's the case, skip to the next
+          // field.
+          if (empty($bundle_field_definitions[$field_name])) {
+            continue;
+          }
           $admin_label = $bundle_field_definitions[$field_name]->getLabel();
         }