I am new to docker and trying to run a hello-world docker image on ubuntu 14.04 desktop. I run into this error every time - “Layer already being pulled by another client. Waiting.”. I have tried restarting docker service and rebooting the machine too. I have enabled cgroup in the grub file. Not sure what else I am missing. I have tried it like 10 times now. The same result every time. Please help.