Internal Server Error

scandir(): Directory name cannot be empty

[lib/bcosca/fatfree-core/base.php:2071] Base->error()
[app/controller/page.php:86] scandir()
[app/controller/page.php:37] Controller\Page->folder()
[lib/bcosca/fatfree-core/base.php:1711] Controller\Page->index()
[lib/bcosca/fatfree-core/base.php:1535] Base->call()
[index.php:240] Base->run()