title: session_start(): Cannot send session cache limiter - headers already sent , but I didn't have any output before my session
body: <p>Sorry for my poor English, 
  I have an error when using session, it was okay when I create others pages with session, but I cannot solve this, please help.</p>
  
  <blockquote>
    <p>Warning: session_start(): Cannot send session cache limiter - headers already sent (output started at /storage/ssd3/402/3124402/public_html/web/samplecode/sessiontest.php:1) in /storage/ssd3/402/3124402/public_html/web/samplecode/sessiontest.php on line 1</p>
  </blockquote>
  
  <p>I only have the following in my php file, I don't have any html output.</p>
  
  <pre><code>&lt;?php 
  session_start();
  ?&gt;
  </code></pre>
  
  <p>Thank you very much!</p>