An error has occurred

Warning: Undefined variable $en_Books in /home/public/e-bible.app/app/inc/func.inc line 21

[1] file: /home/public/e-bible.app/app/inc/func.inc[21]: handle_error(4)
[2] file: /home/public/e-bible.app/app/app.php[202]: require_once(1)
[3] file: /home/public/e-bible.app/index.php[29]: require(1)