If you are running from a new bash instance, and you HAVE the initialization code at your ~/.bashrc, ~/.bash_profile, etc, then you need to check this initialization file for conditionals.
On Ubuntu 14, there is a:
case $- in
*i*) ;;
*) return;;
esac
At line 6, that will halt it's execution if bash is not being ran with the "-i" (interactive) flag. So you would need to run:
bash -i
Also, at the end of the file, there is a
[ -z "$PS1" ] && return
That will halt it's execution if not being ran with $PS1 set (like on a remote ssh session).
If you do not wish to add any env vars or flags, you will need to remove those conditionals from your initialization file.
Hope that's helpful.
nvmbecomes available? - Etan Reisner