I'm running 16.04 from a thumb drive and receiving an error message when I attempt to update package lists.
ubuntu@ubuntu:~$ sudo apt-get update
Ign:1 cdrom://Ubuntu 16.04.4 LTS _Xenial Xerus_ - Release i386 (20180228) xenial InRelease
Hit:2 cdrom://Ubuntu 16.04.4 LTS _Xenial Xerus_ - Release i386 (20180228) xenial Release
Hit:4 http://archive.ubuntu.com/ubuntu xenial InRelease
Get:5 http://security.ubuntu.com/ubuntu xenial-security InRelease [107 kB]
Get:6 http://archive.ubuntu.com/ubuntu xenial-updates InRelease [109 kB]
Fetched 216 kB in 0s (267 kB/s)
** (appstreamcli:5066): CRITICAL **: Error while moving old database out of the way.
AppStream cache update failed.
Reading package lists... Done
Any suggestions?
