Recaptcha: An internal error occurred

I'm using Recaptcha within Django. I was using the following tutorial to integrate it in my web application: http://www.marcofucci.com/tumblelog/26/jul/2009/integrating-reca开发者_运维知识库ptcha-with-django/

The captcha doesn't show up on my machine. Instead of the captcha the following error message is displayed:

An internal error occurred: 4A6376441D250.ADE1949.3546A435

(I get a different code each time).

To which domain did you sign the recaptcha? If you entered "127.0.0.1" in the registration make sure you use this one and not "localhost".

Today, I got this error on one of my client's website.
It was working great but suddenly it stop working. Then upon googling I find this link and renewed my API key.

But after I switched to Secure (SSL Enabled) side of my website then It stops working again.

Then, In I got this function there

recaptcha_get_html(PUBLIC_KEY, $error, true);

The third argumentation use the SSL Server, I've to enable it.
This fixed everything for me.