The server serving this channel expects the user agent to be installed. You apparently do not have the User Agent installed in your php.ini , and you do not install it in the file_get_contents call.
You can set the User Agent for this particular request through the context:
echo file_get_contents( 'http://blog.bosch-si.com/feed/', FALSE, stream_context_create( array( 'http' => array( 'user_agent' => 'php' ) ) ) );
Or globally for any http calls:
ini_set('user_agent', 'php'); echo file_get_contents($link);
Both will give you the desired result.
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