rainloop curl没有下载

I'm trying to install Rainloop on my server. In the documentation its sayed to download rainloop via the curl command "curl -s https://repository.rainloop.net/installer.php | php". When I enter this command nothing happens. And if I enter the command without the "-s" it only shows this:

% Total % Received % Xferd Average Speed Time Time Time Current Dload Upload Total Spent Left Speed

0 0 0 0 0 0 0 0 --:--:-- --:--:-- --:--:-- 0

It looks like the download won't even start. Since there is no error message I don't know what the error is.

Some technical Infos: Ubuntu 16.04.2 LTS Lamp stack is installed Dovecot etc. also

Thanks for possible replys.

I solved it. I was just too stupid :) I missed some dependencies. After that everything worked fine.