WordPress 404 template overriding my .htaccess settings for 404 errors?

Everything is being routed through wordpress so when a request for something like /sub/no_file.html and it doesn't exist, wordpress routes it through its index.php because it satisfies both the !-f and !-d conditions (not an existing file and not an existing directory). It then decides that it can't find the resource for /sub/no_file.html so it then displays its own 404 file.

If you want requests that go to /sub to bypass wordpress' routing so that if a file is requested in /sub/ that doesn't exist, /404.html gets served, you can add this line right before RewriteRule . /index.php [L] in your wordpress rules so that they look like this:

<IfModule mod_rewrite.c>RewriteEngine OnRewriteBase /RewriteRule ^index\.php$ - [L]RewriteCond %{REQUEST_FILENAME} !-fRewriteCond %{REQUEST_FILENAME} !-dRewriteCond %{REQUEST_URI} !^/?sub/RewriteRule . /index.php [L]</IfModule>

The default .htaccess-file will already support the behaviour you want;

# BEGIN WordPress<IfModule mod_rewrite.c>RewriteEngine OnRewriteBase /RewriteRule ^index\.php$ - [L]RewriteCond %{REQUEST_FILENAME} !-fRewriteCond %{REQUEST_FILENAME} !-dRewriteRule . /index.php [L]</IfModule># END WordPress

The magic is in the lines that start with RewriteCond. They instruct Apache to apply the rule RewriteRule . /index.php [L] (which means "any URL will go to index.php"), only when the URL is not an existing file !-f or existing directory !-d.

So this should work by default. The Wordpress rewrite rules do not apply when you try to visit an already existing file.