Below follow the procedure for error to start avast:

My machine is a “Dell Inpiron” with 4GB of memory, and Ubuntu Linux 13.10.

This solution will work for computers with higher memory not low ones.

Insert

SHMMAX=sysctl -n kernel.shmmax
[ $SHMMAX -lt 128000000 ] && sysctl -w kernel.shmmax=128000000

in /usr/lib/avast4workstation/bin/wrapper-script.sh

Then open terminal and type

sudo sysctl -w kernel.shmmax=200000000

Hit Enter.

And then start avast.

Now Avast works!