Apache WordPress subfolder .htaccess: DirectoryIndex not allowed here

I have a working WordPress site that also serves an old flat-file folder. I have set up a clone environment with Ubuntu 22.04 and XAMPP at home and while the WordPress part is fine trying to access the subfolder causes an error.

[Sun Feb 26 17:36:06.779271 2023] [core:alert] [pid 81557] [client 127.0.0.1:37060] /srv/www/site/classic/.htaccess: DirectoryIndex not allowed here

The folder has the same .htaccess file that works on the public site:

DirectoryIndex index.html

If I delete .htaccess I get this error:

[Sun Feb 26 17:42:03.345577 2023] [autoindex:error] [pid 93553] [client 127.0.0.1:48984] AH01276: Cannot serve directory /srv/www/site/classic/: No matching DirectoryIndex (index.php) found, and server-generated directory index forbidden by Options directive

However after deleting .htaccess while you cannot just go to http://site.local/classic/ it will work with explicit pages like http://site.local/classic/index.html.

I definitely don't understand these errors since one seems to contradict the other.

Since I don't have control over my public host's httpd-vhosts.conf I'm assuming the fault lies there but whatever the fix is I'd like to replicate the .htaccess file in a subfolder setting DirectoryIndex rather than just a single fix for this one subfolder.

Relevant portion of httpd-vhosts.conf:

<VirtualHost *:80>
       DocumentRoot "/srv/www/site/"
       ServerName site.local
    <Directory /srv/www/site>
        Options FollowSymLinks
        AllowOverride Limit Options FileInfo
        DirectoryIndex index.php
        Require all granted
    </Directory>
    <Directory /srv/www/site/wp-content>
        Options FollowSymLinks
        Require all granted
    </Directory>
</VirtualHost>

Site root .htaccess (WordPress default):

# BEGIN WordPress
# The directives (lines) between "BEGIN WordPress" and "END WordPress" are
# dynamically generated, and should only be modified via WordPress filters.
# Any changes to the directives between these markers will be overwritten.
<IfModule mod_rewrite.c>
RewriteEngine On
RewriteRule .* - [E=HTTP_AUTHORIZATION:%{HTTP:Authorization}]
RewriteBase /
RewriteRule ^index\.php$ - [L]
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule . /index.php [L]
</IfModule>

# END WordPress

Definitely in learning mode here so all advice is welcome.

> <Directory /srv/www/site>
> Options FollowSymLinks
> AllowOverride Limit Options FileInfo
> DirectoryIndex index.php

To be able to set DirectoryIndex in .htaccess (specifically, to be able to override the DirectoryIndex in a .htaccess context) you need the Indexes directive-type in the AllowOverride directive. For example:

AllowOverride Limit Options FileInfo Indexes

Or, what you see more commonly, is the use of the All keyword (which also includes AuthConfig - to allow the use of the authorization directives). ie. AllowOverride All.

Reference:

• https://httpd.apache.org/docs/2.4/mod/core.html#allowoverride

Note that the WordPress config is dependent on DirectoryIndex index.php being set (for when the homepage is requested). Which you have set in the server config. You can set both in a single directive, for example:

DirectoryIndex index.php index.html

(index.php takes priority in this case.)

If the DirectoryIndex is not set anywhere then the default is index.html only.