Comment 0 for bug 1675184

In Ubuntu 16.04 LTS the file installed by apache2 as /etc/apache2/mods-available/mime.conf includes the following section:

        #
        # Filters allow you to process content before it is sent to the client.
        #
        # To parse .shtml files for server-side includes (SSI):
        # (You will also need to add "Includes" to the "Options" directive.)
        #
        AddType text/html .shtml
        AddOutputFilter INCLUDES .shtml

The AddOutputFilter line needs mod_include to function correctly. If mod_include is not enabled, but mime.conf is enabled, then any request to a file ending on .shtml will cause the following error being printed in the log:

AH00082: an unknown filter was not added: includes

This can be quite irritating.

It can be fixed by only adding the output filter in case the required mod_include is available:

<IfModule mod_include.c>
        AddOutputFilter INCLUDES .shtml
</IfModule>

In case this fix is something Ubuntu does not want to fix but expects from upstream please report accordingly upstream to have a fix included in Ubuntu.

ProblemType: Bug
DistroRelease: Ubuntu 16.10
Package: apache2 (not installed)
ProcVersionSignature: Ubuntu 4.8.0-41.44-generic 4.8.17
Uname: Linux 4.8.0-41-generic x86_64
ApportVersion: 2.20.3-0ubuntu8.2
Architecture: amd64
CurrentDesktop: Unity
Date: Wed Mar 22 14:13:20 2017
InstallationDate: Installed on 2017-02-26 (24 days ago)
InstallationMedia: Ubuntu 16.10 "Yakkety Yak" - Release amd64 (20161012.2)
SourcePackage: apache2
UpgradeStatus: No upgrade log present (probably fresh install)