How to fix lock /var/lib/dpkg/lock – open (11 Resource temporarily unavailable) Error
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?
First thing you need to check Synaptic Package Manager open at the same time
That happens when synaptic or another package update / installation application is already running. Close any other package managers (including Add/Remove application, language pack installer, etc.) and retry.