Zend Framework application.ini - 500内部服务器错误

I am using zend framework 1.11. I'm getting 500 internal server error when i opening the url. I have checked the database connection. It's fine. I don't know where is the problem exactly.

I'm getting the error from the line. $application->bootstrap()->run(); Please guide me to solve this problem.

Some of the reasons are

1. rewrite module is not enabled.
2. htaccess is not configured to redirect request to index.php (usually in public folder)