Since Plasma 5 every KDE distribution cannot be used in VirtualBox with 3d acceleration enabled. Reproducible: Always Steps to Reproduce: If 3D acceleration is enabled, KDEs login screen appears normally, one can login. After logging in, the Desktop appears, everything seems to be normal. BUT: 1.) Right clicking somewhere at the desktop doesn't bring up the context menu 2.) Clicking the "KDE" Menu: the KDE Menu appears, but the Control Bar disappears completely 3.) When starting an application in KDE Menu (which can still be opened with Alt+F1), the application seems to start, but no application window appears 4.) Trying to get out of KDE and switch to a console TTY (STRG+ALT+F1) just switches to a smaller screen but in this KDEs background image remains. ==> So the Desktop is completely unusable, it isn't even possible to get a terminal window, so one even can't examine "glxinfo" or some logs... Actual Results: 3d accelerated GUI elements are hidden (basically the complete shell). Expected Results: 3d acceleration usable. Seems to be mainly related to the VirtualBox graphic driver, however the guys over there are currently struggling. It would be great if someone has an idea about a major change in graphics between Plasma 4 and 5 to give them an idea how to fix this in VirtualBox. All major companies, plattforms and server farms in datacenters seem to be mainly using VMWare, which is working with Plasma 5. However, currently no KDE Linux distribution can be used with the open source VirtualBox, so I doubt we can spread open source for virtual enterprise platforms, if the basics don't work. Would be fantastic if someone can verify this from KDE side.
If virtualbox has a bug, that's virtualboxes problem. We can't do anything. As a workaround, simply don't enable the 3D acceleration flag. As for what's changed, we're using QtQuick - testing with qmlscene is easier than starting plasma.