problem loading google calendar in server #232

I'm trying to implement the google calendar api in my server, i followed the example and it worked fine in localhost, also worked in a test server but when i try to run it in the server i got a error that is:

exception 'Google_AuthException' with message 'Error fetching OAuth2 access token, message: ''' in /var/www/ci/dinamico/cide.pucp.edu.pe/libs/google/auth/Google_OAuth2.php:115 Stack trace: #0 /var/www/ci/dinamico/cide.pucp.edu.pe/libs/google/Google_Client.php(127): Google_OAuth2->authenticate(Array, '4/MJUUDbfPiviAE...') #1 /var/www/ci/dinamico/cide.pucp.edu.pe/ws/plataforma/modules/pages/page.php(32) : eval()'d code(23): Google_Client->authenticate('4/MJUUDbfPiviAE...') #2 /var/www/ci/dinamico/cide.pucp.edu.pe/ws/plataforma/modules/pages/page.php(32): eval() #3 {main}

I've been looking for similar errors around but the common errors have always a the $response string filled but in this case it's empty. I don't know if someone got this error and know hot to fix it. Thanks for your cooperation