Error message inside SEO Ranking widget (no replies)

I got an error and it says I should report it. The widget seem to be working, but I see this error over the other information. I just add it in case it helps for something:

There is an error. Please report the message (Piwik 2.7.0) and full backtrace in the Piwik forums (please do a Search first as it might have been reported already!).

Warning: file_get_contents(http://www.who.is/whois/domain.com): failed to open stream: HTTP request failed! in /var/www/piwik/core/Http.php on line 408

Backtrace -->

#0 Piwik\Error::errorHandler(...) called at [:]
#1 file_get_contents(...) called at [/var/www/piwik/core/Http.php:408]
#2 Piwik\Http::sendHttpRequestBy(...) called at [/var/www/piwik/core/Http.php:94]
#3 Piwik\Http::sendHttpRequest(...) called at [/var/www/piwik/plugins/SEO/RankChecker.php:61]
#4 Piwik\Plugins\SEO\RankChecker->getPage(...) called at [/var/www/piwik/plugins/SEO/RankChecker.php:240]
#5 Piwik\Plugins\SEO\RankChecker->_getAgeWhoIs(...) called at [/var/www/piwik/plugins/SEO/RankChecker.php:150]
#6 Piwik\Plugins\SEO\RankChecker->getAge(...) called at [/var/www/piwik/plugins/SEO/API.php:63]
#7 Piwik\Plugins\SEO\API->getRank(...) called at [/var/www/piwik/plugins/SEO/Widgets.php:41]
#8 Piwik\Plugins\SEO\Widgets->getRank(...) called at [/var/www/piwik/plugins/CoreHome/Controller.php:88]
#9 Piwik\Plugins\CoreHome\Controller->renderWidget(...) called at [:]
#10 call_user_func_array(...) called at [/var/www/piwik/core/FrontController.php:577]
#11 Piwik\FrontController->doDispatch(...) called at [/var/www/piwik/core/FrontController.php:86]
#12 Piwik\FrontController->dispatch(...) called at [/var/www/piwik/core/dispatch.php:34]
#13 require_once(...) called at [/var/www/piwik/index.php:46]