The vboxdrv kernel module is not loaded.
Symptoms:
$ VBoxManage --version WARNING: The vboxdrv kernel module is not loaded. Either there is no module available for the current kernel (5.4.28-1-MANJARO) or it failed to load. Please recompile the kernel module and install it by sudo /sbin/vboxconfig You will not be able to start VMs until this problem is fixed.