I have a droplet here (Linux PhakeApps 3.13.0-36-generic #63-Ubuntu SMP Wed Sep 3 21:30:07 UTC 2014 64 x8664 x86_64 GNU/Linux).
So I decided to make a fresh installation. Several times. Every time the error occures again. I tried installing it by downloading a copy of Ghost, I tried installing it by cloning the repository from Github. Nothing worked.
If you open the dev console, you can see the errors.