virtualbox.org

I have a problem when I installed VirtualBox on my Mac OS.
macOS sierra 10.12.5
VirtualBox 5.1.22

After installed VirtualBox I cannot access my share folders on other windows machine (remote host, not the virtual guest).
I tested by following order.
1. macos cannot access remote share folder, other windows machine can access, so server is works fine.
2. reboot multiple times don't fix the problem.
3. uninstall virtualbox, still cannot access windows share.
4. do a reboot, I can access windows share, the user login prompt window shown.
5. install virtualbox, still can access windows share.
6. do a reboot, I cannot access windows share.
7. add a exit 0 into beginning of /Library/Application Support/VirtualBox/LaunchDaemons/VirtualBoxStartup.sh
8. do a reboot, I can access windows share.

Really strange problem.

After some investigation, I found VBoxNetAdp.kext conflict with tap.kext (from tuntaposx project). remove any one from system fix the problem.
These two kext modules can load on boot, But If I load thest by `kextload` manually, I can only load one module, the second load will return a error `failed to load - (libkern/kext) kext (kmod) start/stop routine failed; check the system/kernel logs for errors or try kextutil(8)`

I started replying to your first post that the installation of VirtualBox has nothing to do with SMB networking on a normal installation, but you seem to have found the conflict. Since the software you're having a problem with is open-source, the developers might have a chance of looking at it and potentially getting it fixed. It might be worth your time to head to the VirtualBox bug tracker, the TunTap bug tracker, or both and have the developers coordinate their fix

EDIT: I see that you already did visit the TunTap tracker: https://sourceforge.net/p/tuntaposx/bugs/25/

Related ticket #16857: VBoxNetAdp.kext conflict with tap.kext on macOS.