title: .htaccess in subfolder for separate 404 page
body: <p>I'm trying to have a separate 404 page for a subfolder of public_html. The .htaccess of the subfolder reads:</p>
  
  <pre><code>ErrorDocument 404 /subfolder/404.html
  </code></pre>
  
  <p>But 404 errors in the subfolder just come up as 500 Internal Server Errors, with the message </p>
  
  <pre><code>"Additionally, a 500 Internal Server Error error was encountered while trying to use an ErrorDocument to handle the request."
  </code></pre>
  
  <p>I think this might be due to the mess of an .htaccess the root has. There's a Wordpress install in the root folder so this</p>
  
  <pre><code># Use PHP5.4 Single php.ini as default
  AddHandler application/x-httpd-php54s .php
  
  # BEGIN WordPress
  &lt;IfModule mod_rewrite.c&gt;
  RewriteEngine On
  RewriteBase /
  RewriteRule ^index\.php$ - [L]
  RewriteCond %{REQUEST_FILENAME} !-f
  RewriteCond %{REQUEST_FILENAME} !-d
  RewriteRule . /index.php [L]
  &lt;/IfModule&gt;
  
  # END WordPress
  # Set PHP handler to application/x-httpd-phpbeta on Mon Jan 11 15:10:53    MST 2016.
  </code></pre>
  
  <p>is what I get. I can't really make heads or tails of it, but why is it stopping my .htaccess from working?</p>