Dispatcher class and class '' Router '' not found

Question

What I've done:

I am doing a project in CakePHP 2.2.3 . It worked fine until it made some changes to css. What happened

When I refresh the page in the browser, I get the following error

 Fatal error: Class 'Dispatcher' not found on my site path/app/webroot/index.php on line 91 Fatal error: Class 'Router' not found 

FYI I already cleared the entire cache.