Just installed Kubuntu and corrupted application icons appear randomly on my task bar. Does it happen to anyone else?
Here's how it looks like:
In my experience, this usually happens if you're using the nouveau video driver, or some other video driver that does not work well with the KDE/Qt icon cache.
Technical details aside, I haven't been able to figure out a way to fix the issue without using a different video driver. If you have an NVIDIA video card, a possible solution would be to install the proprietary nvidia drivers, available from the "restricted drivers" application.
You can enable these drivers by opening up the [K] menu , selecting "Applications", then "System", and start the "Additional drivers" application to install the nvidia drivers.