Issue #1924278 by marcingy, chx, dawehner: Fixed Fatal error: Class 'Drupal\Core\Database\DatabaseNotFoundException' not found.

core/lib/Drupal/Core/Database/DatabaseNotFoundException.php

@@ -0,0 +1,12 @@
+<?php
+/**
+ * @file
+ * Contains Drupal\Core\Database\DatabaseNotFoundException.
+ */
+
+namespace Drupal\Core\Database;
+
+/**
+ * Exception thrown if specified database is not found.
+ */
+class DatabaseNotFoundException extends \RuntimeException {}