I have Kubuntu 16.04 running under Virtualbox 5.1.22 on a Windows 7 host. Plasma crashes intermitently when mouse pointer goes over the bottom panel. The panel disappears for a short time, then reappears, and a Plasma error box appears. No running applications are affected. Have tried a few different 5.x versions of Virtualbox. 3D acceleration is turned off. Have tried increasing RAM on guest system. Tried multiple Windows 7 host systems
I have exactly the same thing. I can also 100% reproduce the error. The cause is the interaction between the plasma task bar and the VirtualBox menu.
System details: Win10 Pro (Host) Kubuntu 16.04 (Guest) VirtualBox 5.2.6 VB view mode full screen
Pin the VBox menu to the top (in settings before you start Kubuntu)
- Open several windows so there are a few tabs on the task bar (at the bottom)
- hover over icons on the task bar, allow the preview to pop up - All is good
- Open any menu on the VirtualBox menu at the top (or pop it up if you had not got it pinned)
- hover over any tab till the preview pops up
- plasma crashes
NOTE: timing is important. If you close the menu and count to 10s while the mouse is not over the task bar then the preview will work correctly.