Apache file negotiation failed

I found the solution. Very easy, indeed. I forgot to include the following:

AddType application/x-httpd-php .php

into apache mod_mime section into httpd.conf

I was misled by the fact that php scripts were correctly working; however the negotiation was failing because mod_negotiation only looks for "interesting" (and known) file types.

I had the same problem after updating from Debian Squeeze to Wheezy. The mods-enabled/mime.conf includes the known file types from the system:

TypesConfig /etc/mime.types

The problem was that the /etc/mime.types file was replaced by the update and in the replaced file, the PHP part was commented out. When searching for it, I found:

#application/x-httpd-php                        phtml pht php
#application/x-httpd-php-source                 phps
#application/x-httpd-php3                       php3
#application/x-httpd-php3-preprocessed          php3p
#application/x-httpd-php4                       php4
#application/x-httpd-php5                       php5

I had to remove the # from each line containing php-relevant stuff, then save and restart the Apache web server. That solved the problem without modifying the mime.conf file.

Instead of mapping .php to a media type (which can have security implications, as described in Debian Bug 589384 which disabled them), you can configure MultiviewsMatch to match files without a type for .php, as suggested in Mark Amery's answer to a similar question:

<Files "*.php">
    MultiviewsMatch Any
</Files>

I had the same problem after updating from Debian Squeeze to Wheezy. The mods-enabled/mime.conf includes the known file types from the system:

 TypesConfig /etc/mime.types

The problem was that the /etc/mime.types file was replaced by the update and in the replaced file, the PHP part was commented out. When searching for it, I found:

#application/x-httpd-php                        phtml pht php
#application/x-httpd-php-source                 phps
#application/x-httpd-php3                       php3
#application/x-httpd-php3-preprocessed          php3p
#application/x-httpd-php4                       php4
#application/x-httpd-php5                       php5

I had to remove the # from each line containing php-relevant stuff, then save and restart the Apache web server. That solved the problem without modifying the mime.conf file.