I am using Docker version 1.12.2, build bb80604 and VirtualBox 5.1.6.
Docker version 1.12.2, build bb80604
VirtualBox 5.1.6
I was able to install Docker Toolbox correctly but I am
Docker Toolbox
step 1: run: docker-machine rm -f default - (on your mac terminal or control panel)
docker-machine rm -f default
step 2: run: docker-machine create -d virtualbox --virtualbox-memory 2048 default
docker-machine create -d virtualbox --virtualbox-memory 2048 default
It worked like miracle.