For VirtualBox support you need to go to e.g. https://www.virtualbox.org/wiki/Community, doubt that the Kali team is providing support for tools they are just packaging.

Sorry but you will have to be much more detalled.

What version of Kali, how was it installed (pre-made image or installed via the installer image), which version of virtualbox, running on which host (windows, mac, linux), what is the issue exactly, what are the steps to reproduce, can you share logs, screnshots, etc etc.. Please read https://www.kali.org/docs/community/submitting-issues-kali-bug-tracker/ for more inspiration.

In the meantime I'm closing this ticket, feel free to re-open (or open a new one) after you have enough information. Thanks!