make sure that for every deb entry in /etc/apt/sources.list you have a matching deb-src entry. The rest of the line must be identical.
something like deb-src http://in.archive.ubuntu.com/ubuntu xenial main. enable deb-src in /etc/apt/sources.list [removing the comments will help to enable it] -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1433906 Title: Acer, Inc ID 5986:055a is useless after 14.04.2 installed. To manage notifications about this bug go to: https://bugs.launchpad.net/hwe-next/+bug/1433906/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs