Undefined array key "HTTP_REFERER"

Fehler sind aufgetreten

Fehlermeldung Undefined array key "HTTP_REFERER"
Datei /app/resst/controllers/RouterController.php
Zeile 42
Trace #0 /app/resst/controllers/RouterController.php(42): log_error(2, 'Undefined array...', '/app/resst/cont...', 42) #1 /app/html/index.php(66): RouterController->process(Array, Object(DB), Object(AppConfig)) #2 {main}