--convert-to --headless hangs on Ubuntu 14.04

Hey guys! I’m trying to do some document converting using the following command string on an Ubuntu 14.04 installation:

soffice --headless --convert-to html letter.doc

However, it hangs every time and displays no output, even when I switch document types and files, forcing me to Ctrl-C in order to quit. I know LibreOffice itself is working because if I just run “soffice” the GUI version comes up, and doing an soffice --headless gives me the command-line list of arguments. Do you happen to know what would be causing the hanging? Thank you for your help!

I’m having the same issue. Libreoffice 4.2.8 on ubuntu 14.04