I have the same problem, and it happens with both apt-get and synaptic when I try to update the list of packages.
It has nothing to do with installing without an internet connection, as for me this just started happening tonight (it worked fine before). A "workaround" is to remove the appstream package, which also removes the GNOME/Ubuntu Software package (the GUI software installer), which is fine for me (I never use those anyway), but probably not for "regular" users... -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1583845 Title: Can't "apt-get update" - appstreamcli stuck at 100% Processor Utilization To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/appstream/+bug/1583845/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs