@GeneArch I cannot reproduce your issue. VirtualBox is loading fine for me and everything is working as expected. Tested with Plasma and LXQt.
You said Plasma 5.11.1 but I think that you mean Qt 5.11.1, because Plasma is currently at 5.13.3.
Here is a link to a possibly related problem: https://www.virtualbox.org/pipermail/vbox-dev/2018-July/015046.html.
Please share your solution if you find something.
Pinned Comments
dbermond commented on 2022-10-21 19:08 (UTC)
Notice:
To avoid crashes when upgrading Guest Additions from version 6.x to 7.x on Windows guests, uninstall the old Guest Additions first, then reboot, and then install the new ones. It's recommended to do all these operations in Safe Mode. See this upstream bug ticket for more details.