title: RewriteEngine on casuses error 500
body: <p>I am tring to write a rewrite engine. 
  So I have written this in the .htaccess file:</p>
  
  <pre><code>RewriteEngine on
  
  RewriteCond %{REQUEST_FILENAME} !-d
  RewriteCond %{REQUEST_FILENAME} !-f
  RewriteCond %{REQUEST_FILENAME} !-l
  
  RewriteRule     ^(.+)$ index.php?url=$1 [QSA, L]
  </code></pre>
  
  <p>I get a 500 error msg. </p>
  
  <p>I checked the httpd.conf file and this line</p>
  
  <pre><code>LoadModule setenvif_module modules/mod_setenvif.so
  </code></pre>
  
  <p>is not commented out..</p>
  
  <p>I also tried to comment out all these line from the .htaccess file like so,</p>
  
  <pre><code>#RewriteEngine on
  
  #RewriteCond %{REQUEST_FILENAME} !-d
  #RewriteCond %{REQUEST_FILENAME} !-f
  #RewriteCond %{REQUEST_FILENAME} !-l
  
  #RewriteRule     ^(.+)$ index.php?url=$1 [QSA, L]
  </code></pre>
  
  <p>but I still get a 500 error.
  What else can I look at?</p>