VirtualBox 5.1.8 installation didn't install kernel extensions. How do I fix this? [macOS 10.13] When I installed VirtualBox it said that the installation "failed" but I still got VirtualBox.app in my applications folder.
When I try to boot windows 7 VM, it says "Kernel drivers not installed (rc = -1908).
Online solutions are saying I should "restart the host". I checked my StartupItems folder and it's empty.


So I guess the installer failed to install kernel extensions.

So there's this thing called SIP which prevents installing kernel extensions. Should I disable it for now?

What do I do? I need a Windows virtual machine in 8 hours...
High Sierra comes with a new security feature: Secure Kernel Extension Loading, which blocks kernel extension loading. The implementation appears to be questionable.

To allow the loading of some non-Apple kernel extension you have to either allow execution in Preferences > Security &amp; Privacy > General:



or disable the security feature with a Terminal command (not recommended):

sudo spctl --master-disable