Login Admin

[Adriana drigues]

Quando tento logar com admin após a instalação ocorre o seguinte erro:

Warning: main(classes/admin.php): failed to open stream: No such file or directory in /home/mariadal/public_html/mambo/administrator/index2.php on line 30

Fatal error: main(): Failed opening required \'classes/admin.php\' (include_path=\'.:/usr/lib/php:/usr/local/lib/php\') in /home/mariadal/public_html/mambo/administrator/index2.php on line 30

Como solucionar?

Obrigada