Found the problem. Had any of us looked at unity8-dash.log (attached) we would have seen it.
The problem is that MainView uses Ubuntu.PerformanceMetrics but that package is never installed. Solution: sudo apt install qml-module-ubuntu-performancemetrics So the bug is just Unity8 missing a hard dependency on that package which it requires. ** Changed in: unity8 (Ubuntu) Status: New => Triaged -- You received this bug notification because you are a member of Ubuntu Touch seeded packages, which is subscribed to unity8 in Ubuntu. https://bugs.launchpad.net/bugs/1577639 Title: Scopes and System Settings (all my QML apps) show just blank white windows [missing package qml-module-ubuntu-performancemetrics] Status in ubuntu-ui-toolkit package in Ubuntu: New Status in ubuntu-ui-toolkit-gles package in Ubuntu: New Status in unity8 package in Ubuntu: New Bug description: Scopes and System Settings (all my QML apps) show just blank white windows. However the web-browser and Mir demos render correctly. ProblemType: Bug DistroRelease: Ubuntu 16.04 Package: unity8 8.12+16.04.20160401-0ubuntu1 ProcVersionSignature: Ubuntu 4.4.0-21.37-generic 4.4.6 Uname: Linux 4.4.0-21-generic x86_64 ApportVersion: 2.20.1-0ubuntu2 Architecture: amd64 Date: Tue May 3 12:05:54 2016 InstallationDate: Installed on 2015-12-03 (151 days ago) InstallationMedia: Ubuntu 16.04 LTS "Xenial Xerus" - Alpha amd64 (20151202) SourcePackage: unity8 UpgradeStatus: No upgrade log present (probably fresh install) To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/ubuntu-ui-toolkit/+bug/1577639/+subscriptions -- Mailing list: https://launchpad.net/~touch-packages Post to : touch-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~touch-packages More help : https://help.launchpad.net/ListHelp