If you get this error or find it in the error log.
…file_get_contents() [function.file-get-contents]: http:// wrapper is disabled in the server configuration by allow_url_fopen=0 in…
You have to edit the php.ini and enable the following setting.
allow_url_fopen = On
Restart Apache and it should be fixed.
If you do not have the ability to modify your php.ini file please contact your hosting provider for that.