title: Paypal Button: sandbox vs production
body: <p>I'm trying to integrate a Paypal Button but I'm getting error on sandbox while it looks working on production.</p>
  
  <p>The code is:</p>
  
  <pre><code>&lt;form action="https://www.paypal.com/cgi-bin/webscr" method="post"&gt;
  &lt;!-- &lt;form action="https://www.sandbox.paypal.com/cgi-bin/webscr" method="post"&gt; --&gt;
  
    &lt;input type="hidden" name="business" value="email@accountonsandbox.local"&gt;
  
    &lt;input type="hidden" name="cmd" value="_xclick"&gt;
  
    &lt;input type="hidden" name="no_shipping" value="1"&gt;
    &lt;input type="hidden" name="return" value="http://return_url"&gt;
    &lt;input type="hidden" name="cancel_return" value="http://cancel_url"&gt;
    &lt;input type="hidden" name="rm" value="1"&gt;
    &lt;input type="hidden" name="cbt" value="Back"&gt;
    &lt;input type="hidden" name="notify_url" value="http://notify_url"&gt;
    &lt;input type="hidden" name="custom" value="customdata"&gt;
  
    &lt;input type="hidden" name="item_name" value="item_name"&gt;
    &lt;input type="hidden" name="amount" value="6"&gt;
    &lt;input type="hidden" name="currency_code" value="EUR"&gt;
  
    &lt;img alt="" border="0" width="1" height="1"
    src="https://www.paypalobjects.com/en_US/i/scr/pixel.gif" &gt;
  
    &lt;input type="hidden" name="lc" value="it_IT"&gt;
  
    &lt;!-- Display the payment button. --&gt;
    &lt;input type="image" name="submit" border="0" width="140"
      src="https://www.paypalobjects.com/webstatic/en_US/btn/btn_paynow_cc_144x47.png"
      alt="Paga con PayPal"&gt;
  &lt;/form&gt;
  </code></pre>
  
  <p>If the first line is production, it works (I see paypal's page to make payment), if I switch with line 2 (sandbox) I'm getting an internal server error from paypal's server showing the error page.</p>
  
  <p>This situation is going on by more than 10 days but I can't deploy it in production without test it.</p>
  
  <p>Sandbox status shows that everything is working, I don't have idea how to solve this.</p>
  
  <p>UPDATE
  The error is: <a href="https://imgur.com/a/vF3wC" rel="nofollow noreferrer">http://imgur.com/a/vF3wC</a>
  It's in italian, translating it should be something like: There was a system error. Try later.</p>