A lot of things.

app/Helpers/EntryHelpers.php

@@ -48,6 +48,8 @@ class EntryHelpers {
      */
     public static function buildCompleteTitle( string $section, array $fields = [] ){
 
+        $fields = array_merge( ['entry_title' => 'Untitled', 'game_name' => '', 'languages_string' => '', 'platform_name' => ''], $fields );
+
         return match ($section) {
             'translations' => sprintf('%s (%s Translation) %s', $fields['entry_title'] ?? $fields['game_name'], $fields['languages_string'], $fields['platform_name']),
             'romhacks' => sprintf('%s (%s) Romhack', $fields['entry_title'], $fields['platform_name']),