tab auto completion not working (/etc/bash_completion not working)?

Question

i am on an old ubuntu environment (Ubuntu 12.04.5 LTS) and bash_completion is not working even i included it in my .bashrc:

if [ -f /etc/bash_completion ]; then
. /etc/bash_completion
fi

i tried including /etc/bash_bashrc, but still not working:

if [ -f /etc/bash_bashrc ]; then
. /etc/bash_bashrc
fi

user@old_skunk:~:$ cd loca-bash: exclude: unbound variable

user@old_skunk:~:$ls -al loca-bash: !ref: unbound variable
-bash: !ref: unbound variable
-bash: !ref: unbound variable
-bash: words[i]: unbound variable

Answer 1

I used this script and everything is well

sudo apt-get install --reinstall bash-completion