I’ve been using the Dropbox Linux client on my server for a while now, it’s very handy for sync’ing files to & from my various systems.
I recently installed a new server and hit the problem that following the usual instructions:
cd ~ && wget -O - "https://www.dropbox.com/download?plat=lnx.x86_64" | tar xzf -
resulted in Dropbox not starting.
The problem (according to its crash log) was that it was trying to link against libgtk which I didn’t have installed on my (headless) Ubuntu Server 14.04 installation.
After a bit of messing around I realized that the problem was that I had enabled ForwardX11 on my PuTTY sessions and so dropboxd thought that I had an X11 session available. When I disabled X11 forwarding the problem went away & dropboxd ran as normal.