I'm running FreeBSD 13.0-RELEASE in VirtualBox with virtualbox-ose-additions-6.1.18_1 and virtualbox-ose-kmod6.1.18_1 and whenever I start Plasma, ether through sddm or xinit, it stays stuck on the loading screen. When I disable vboxguest and vboxservice then Plasma is able to start.
If you have not already done so: 1. stop the guest 2. set the guest to use VBoxSVGA
See if it works with guest additions for a user who is not a member of wheel. If so, then it's probably the same issue described here: https://github.com/outpaddling/desktop-installer/issues/8
(In reply to Graham Perrin from comment #1) this was the issue, switching graphics controllers worked perfectly
(In reply to kam from comment #3) Thank you for confirming. Related: bug 254266 comment 7 – I'm to edit the package message, maybe later this week. For fewer users of emulators/virtualbox-ose-additions to have the pitfalls of VMSVGA …
Closing this as "Not a bug", meaning that this is not "our" (kde@) bug. Since the problem with VMSVGA vs VBoxSVGA is well known, there is no point to keep this bug open.
<https://github.com/freebsd/freebsd-ports/pull/115> > Update package descriptions and messages for some VirtualBox ports > … Draft; comments and corrections are invited. Thank you.