The insighttoolkit4 source was deleted from Wily's release pocket on 2015-08-12, which means your apt sources are using the proposed pocket. I'd recommend removing that, as -proposed can contain packages that are not installable like this one. insighttoolkit4 will return in Xenial.
If you would like for it to be backported, please use the request- backport tool from ubuntu-dev-tools. ** Changed in: insighttoolkit4 (Ubuntu) Status: New => Won't Fix -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1517591 Title: package not installable To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/insighttoolkit4/+bug/1517591/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs