Those are just warnings that your /etc/apt/sources.list and /etc/apt/sources.list.d/ have become slightly broken due to the use of PPAs. Unfortunately this is not a bug in regular Ubuntu so you will need to fix those errors yourself.
** Package changed: xorg (Ubuntu) => ubuntu ** Changed in: ubuntu Status: New => Invalid -- You received this bug notification because you are a member of Ubuntu-X, which is subscribed to xorg in Ubuntu. https://bugs.launchpad.net/bugs/1802504 Title: TILIX INFO To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+bug/1802504/+subscriptions _______________________________________________ Mailing list: https://launchpad.net/~ubuntu-x-swat Post to : ubuntu-x-swat@lists.launchpad.net Unsubscribe : https://launchpad.net/~ubuntu-x-swat More help : https://help.launchpad.net/ListHelp