Issue #3272830 by acbramley: Update index throws exception if index doesn't exist

src/SearchAPI/BackendClient.php

@@ -257,8 +257,14 @@ class BackendClient implements BackendClientInterface {
    * {@inheritdoc}
    */
   public function updateIndex(IndexInterface $index): void {
-    $index->clear();
-    $this->updateFieldMapping($index);
+    if ($this->indexExists($index)) {
+      $index->clear();
+      $this->updateSettings($index);
+      $this->updateFieldMapping($index);
+    }
+    else {
+      $this->addIndex($index);
+    }
   }
 
   /**