It should be noted that for Opera users in the meantime, you should disable the auto-update feature within Opera and manually correct the "https://"; typo in /etc/apt/sources.list.d/opera-stable.list as root.
For example, from the terminal: $ sudo pluma /etc/apt/sources.list.d/opera-stable.list -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1663523 Title: Adding Opera Browser from Software Boutique breaks apt in Ubuntu Mate 16.04.1 To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu-mate/+bug/1663523/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
