Problem
While using GetSimple with FancyURLs (Apache Rewrite), every menu item nested under the home page returned a 404.
The (rewritted) URL of the home page is /index
The sub-pages URLs are rendered as index/something, and triggered a 404 error.
Solution
Disable MultiViews.
MultiViews is an Apache mechanism for automatically switching wich document is sent to the user, based on the Accept header. Because the front controller is named index.php, MultiViews was trying to reach index.php/something instead of (as specified in RewriteRules) index.php?id=index/something.
How to do it
Open the GetSimple .htaccess file, and locate :
Options -Indexes
Change to :
Options -Indexes -MultiViews