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://api.piwik.org/1.0/getLatestVersion/?piwik_version=2.7.0&php_version=5.6.15&url=https%3A%2F%2Fpiwik.blzk.de%2Findex.php&trigger=Proxy&timezone=Europe%2FBerlin): failed to open stream: Ein Verbindungsversuch ist fehlgeschlagen, da die Gegenstelle nach einer bestimmten Zeitspanne nicht richtig reagiert hat, oder die hergestellte Verbindung war fehlerhaft, da der verbundene Host nicht reagiert hat. in C:\Apache24\htdocs\piwik\core\Http.php on line 408

Backtrace -->

#0 Piwik\Error::errorHandler(...) called at [:]
#1 file_get_contents(...) called at [C:\Apache24\htdocs\piwik\core\Http.php:408]
#2 Piwik\Http::sendHttpRequestBy(...) called at [C:\Apache24\htdocs\piwik\core\Http.php:94]
#3 Piwik\Http::sendHttpRequest(...) called at [C:\Apache24\htdocs\piwik\core\UpdateCheck.php:72]
#4 Piwik\UpdateCheck::check(...) called at [C:\Apache24\htdocs\piwik\plugins\CoreUpdater\CoreUpdater.php:151]
#5 Piwik\Plugins\CoreUpdater\CoreUpdater->updateCheck(...) called at [:]
#6 call_user_func_array(...) called at [C:\Apache24\htdocs\piwik\core\EventDispatcher.php:116]
#7 Piwik\EventDispatcher->postEvent(...) called at [C:\Apache24\htdocs\piwik\core\Piwik.php:784]
#8 Piwik\Piwik::postEvent(...) called at [C:\Apache24\htdocs\piwik\core\FrontController.php:437]
#9 Piwik\FrontController->init(...) called at [C:\Apache24\htdocs\piwik\core\dispatch.php:33]
#10 require_once(...) called at [C:\Apache24\htdocs\piwik\index.php:46]


Invalid Referrer detected - This means that your web browser is not sending the "Referrer URL" which is required to proceed with the redirect. Verify your browser settings and add-ons, to check why your browser is not sending this referrer.

You can access the page at: http://forum.piwik.org