This issue happens only on UEFI systems with enabled Secure Boot.
When I try to install DKMS modules like VirtualBox, Nvidia, or Broadcom drivers, they do not install and I get
Required key not available when I try to
VirtualBox complains that
vboxdrv is not loaded.
wl driver is shown in
lspci -k as a kernel module but is not in use.
sudo modprobe wl throws
Required key not available.
Also this issue may happen when I install some kernel modules from git sources.
This issue may appear after a kernel update as disabled wireless adapter, black screen after a reboot, etc.
How can I fix it?