If the problem is happening when you search plugins or themes its probably because your connected to a proxy and you need to configure it on your wp-config.php
/** EXAMPLE – proxy settings */
define(‘WP_PROXY_HOST’, ‘proxy.url.com’);
define(‘WP_PROXY_PORT’, ‘1234’);
define(‘WP_PROXY_USERNAME’, ”);
define(‘WP_PROXY_PASSWORD’, ”);
define(‘WP_PROXY_BYPASS_HOSTS’, ‘localhost’);