SMF Forum - Template Parse Error instead of normal PHP errors

Currently I am working on an existing website that was initially created using SMF Forum. The problem is that I every time an error occurs in the code, it will only display:

Template Parse Error!

It seems something has gone sour on the forum with the template system. This problem should only be temporary, so please come back later and try again. If you continue to see this message, please contact the administrator.

You can also try refreshing this page.

This is really annoying during development. How do I setup SMF Forum to display errors?

The file index.php does already contain the following codes:

error_reporting(E_ALL);
ini_set('display_errors', 1);

The problem is solved.

As I was getting the error on the registration page, I was not logged in. To see more information about errors, you will need to have Administrator privileges.

So I logged in and navigated to the registration page and saw the error message.