Debug codeigniter

[eluser]Unknown[/eluser]
Hello,

I moved an app from an old server to AWS.
Now I get

404 page not found

error when I try to browsing the page.
I read that problem could be depends from .htaccess but it looks good.
I'm using apache 2.4 and the directive AllowOverride is setup to All
Could someone please explain me how I can debug the application for, at least, printing some messages on video that helps me to understand what happen?
On the error.log of Apache nothing appears, and it's set to Debug.

Thanks in adavance,

Regards.

[eluser]InsiteFX[/eluser]
Try changing your ./application/config/config.php uri_protocol