VirtualBox - VERR_INTNET_FLT_IF_NOT_FOUND

If you encounter VERR_INTNET_FLT_IF_NOT_FOUND when you starts up a Virtual Box VM and the host-only adaptor is present (e.g device is installed at Network Connection and enabled), there is a possible that the Device Name is wrong.

If you look at Network Connections from Windows 10 Control Panel, you should see "VirtualBox Host-Only Ethernet Adapter"

When I encounter VERR_INTNET_FLT_IF_NOT_FOUND, the name was "VirtualBox Host-Only Ethernet Adapter #2".

The way to resolve this for me is

1) Uninstall the existing VirtualBox (this won't erase your data)

2) Look at Network Connections and make sure all VirtualBox adaptor is removed

3) Reinstall VirutalBox with "Run as Administrator"

4) After installation, you may see the adaptor named as "VirtualBox Host-Only Ethernet Adapter #2"

5) If you see 4), restart your machine. (Or, you should restart your machine after installing VirtualBox anyway). 

6) After restart, Windows 10 will automatically rename "VirtualBox Host-Only Ethernet Adapter #2" to "VirtualBox Host-Only Ethernet Adapter"

7) Start your VM and test it out.

Reference: https://www.virtualbox.org/ticket/14832