Can't install new theme and Error on Plugins page

Hi Team,

I am getting this error while acessing plugins page. And I couldn’t able install new theme. Please help me

[b]There is an error. Please report the message (Piwik 2.4.1) and full backtrace in the Piwik forums (please do a Search first as it might have been reported already!).

Warning: file_get_contents(http://plugins.piwik.org/api/1.0/plugins?keywords=&query=&sort=) [function.file-get-contents]: failed to open stream: HTTP request failed! in C:\wamp\www\piwik\core\Http.php on line 406

Backtrace -->

#0 Piwik\Error::errorHandler(…) called at [:]
#1 file_get_contents(…) called at [C:\wamp\www\piwik\core\Http.php:406]
#2 Piwik\Http::sendHttpRequestBy(…) called at [C:\wamp\www\piwik\core\Http.php:94]
#3 Piwik\Http::sendHttpRequest(…) called at [C:\wamp\www\piwik\plugins\CorePluginsAdmin\MarketplaceApiClient.php:145]
#4 Piwik\Plugins\CorePluginsAdmin\MarketplaceApiClient->fetch(…) called at [C:\wamp\www\piwik\plugins\CorePluginsAdmin\MarketplaceApiClient.php:116]
#5 Piwik\Plugins\CorePluginsAdmin\MarketplaceApiClient->searchForPlugins(…) called at [C:\wamp\www\piwik\plugins\CorePluginsAdmin\Marketplace.php:45]
#6 Piwik\Plugins\CorePluginsAdmin\Marketplace->getAvailablePluginNames(…) called at [C:\wamp\www\piwik\plugins\CorePluginsAdmin\Controller.php:244]
#7 Piwik\Plugins\CorePluginsAdmin\Controller->createPluginsOrThemesView(…) called at [C:\wamp\www\piwik\plugins\CorePluginsAdmin\Controller.php:256]
#8 Piwik\Plugins\CorePluginsAdmin\Controller->plugins(…) called at [:]
#9 call_user_func_array(…) called at [C:\wamp\www\piwik\core\FrontController.php:531]
#10 Piwik\FrontController->doDispatch(…) called at [C:\wamp\www\piwik\core\FrontController.php:84]
#11 Piwik\FrontController->dispatch(…) called at [C:\wamp\www\piwik\core\dispatch.php:34]
#12 require_once(…) called at [C:\wamp\www\piwik\index.php:47][/b]

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