Upgrade Error - Could not get lock

[Marty]

E: Could not get lock /var/lib/dpkg/lock-frontend. It is held by process 11600 (apt-get)
E: Unable to acquire the dpkg frontend lock (/var/lib/dpkg/lock-frontend), is another process using it?

[stevef]

Marty,

I've split your post to a new thread.

That message is usually triggered when an update process is already active when a second update process is initiated, for example starting a manual check when an automated background check is already running.

Usually just waiting is all that is needed.  Let us know if the symptom continues.