I have just installed Virtualbox from standard 20.04 ubuntu repository:
virtualbox-dkms/focal-updates,now 6.1.16-dfsg-6~ubuntu1.20.04.1 amd64 (installed) virtualbox-qt/focal-updates,now 6.1.16-dfsg-6~ubuntu1.20.04.1 amd64 (installed,automatic) virtualbox/focal-updates,now 6.1.16-dfsg-6~ubuntu1.20.04.1 amd64 (installed)
When I run it from console (or alt-f2 edit box) I see “empty window”. I run this on a 4K monitor running with a native resolution
However when I run it as “run_scaled virtualbox” then there is no problem.
When I change scaling on my monitor from 200% to 100% then the application runs fine, however this is not a solution.
How can I solve it? For now I replaced the binary with a “wrapper” that adds-in run_scaled, but this makes the VBox blurry, as it is a scaled up HD window.
This is what it looks like:
virtualbox on 4k monitor