Unable to lock the administration directory (/var/lib/dpkg/), is another process using it?

Question

root@moonlight:~# apt-get install openssh-server
E: Could not get lock /var/lib/dpkg/lock - open (11: Resource temporarily unavailable)
E: Unable to lock the administration directory (/var/lib/dpkg/), is another process using it?

Answer 1

One unfortunately cannot have two programs that use 'apt' running at the same time. That means you can't run software center & synaptic, or try to run either while doing apt-get something in the terminal. Trying to run two of these applications simultaneously will result in the error you posted. So close down synaptic and/or the software center, and it should be fixed.