Fix

api/common/Service/FileHandler.php

@@ -60,6 +60,9 @@ class FileHandler {
         $output = [];
         foreach ($this->folders as $f) {
             $folder = implode(DIRECTORY_SEPARATOR, [$this->base_folder, $f]);
+            if (!file_exists($folder)) {
+                continue;
+            }
             $files = new \DirectoryIterator($folder);
             foreach ($files as $file) {
                 if ($file->isDir()) {