I have tried to install the development ISO for Kubuntu 19.04 and ran into this issue. Current ISO is from 12/5/2018.
Apparently this issue is resolved in the new build at http://cdimage.ubuntu.com/kubuntu/da...ve/20181207.1/ New issue - install windows in Virtualbox are too small to display all the buttons on the install screens. Therefore I had to blindly hit the tab key to hit the next buttons via the enter key.
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