VirtualBox Host Only Adaptor Disappeared

Solved: VirtualBox Error ‘Interface is not a Host-Only Adapter interface’ (VERR_INTERNAL_ERROR)

Introduction: The Missing Host-Only Adapter Fix

Welcome back to Darren’s Tech Tutorials!

If you’ve recently updated your Windows 10 or 11 machine and suddenly found that your trusted VirtualBox setups stopped networking—you are definitely not alone. Many users, including me, have encountered the deeply frustrating error:

Interface ('VirtualBox Host-Only Ethernet Adapter') is not a Host-Only Adapter interface (VERR_INTERNAL_ERROR).

This error means that VirtualBox can no longer find the specific network interface it needs to allow your host machine (your PC) to communicate directly with your virtual machines (VMs). Essentially, the Windows update ate your Host-Only Adapter configuration.

The great news? This is a straightforward fix! We just need to manually recreate the missing Host-Only Adapter and then reassign it to your virtual machines. Let’s dive right in and get your VirtualBox networking back up and running smoothly!

What Caused the VERR_INTERNAL_ERROR?

The core problem lies in a broken or missing configuration entry within VirtualBox’s networking settings.

When Windows performs a major update, sometimes it cleans up or overrides existing network adapter configurations, especially those created by third-party applications like VirtualBox. When VirtualBox tries to start a VM that is configured to use an adapter that no longer exists in the operating system, it throws the VERR_INTERNAL_ERROR.

To resolve this, we will follow two simple steps:

1. Create a brand new Host-Only Adapter within the VirtualBox Manager.
2. Update the network settings of your affected VMs to point to this new adapter.

Step 1: Recreating the VirtualBox Host-Only Adapter

This is the central step to resolving the error. We need to tell VirtualBox to generate a fresh, clean Host-Only network adapter that Windows recognizes.

1. Open VirtualBox Manager: Ensure all your virtual machines are powered off before starting this process.
2. Access Host Network Manager: Navigate to File in the main menu bar, and then select Host Network Manager. (Note: In some older versions, this might be under Tools or Preferences.)
3. Check Existing Adapters: Look at the list of existing Host-Only Adapters. You will likely see nothing, or perhaps an entry that seems broken or greyed out.
4. Create a New Adapter: Click the Create button (often represented by a green ‘Add’ icon or simply the word ‘Create’). VirtualBox will immediately generate a new adapter, usually named something like VirtualBox Host-Only Ethernet Adapter #2 (or similar).
5. Verify Configuration:
   • Under the Adapter tab, ensure the IPv4 Address is set to a private range (e.g., 192.168.56.1) and the network mask is 255.255.255.0.
   • Under the DHCP Server tab, confirm that Enable Server is checked. This allows the new adapter to assign IP addresses to your VMs automatically.
6. Apply and Close: Click Apply or Close to save the new adapter configuration.

You now have a clean, working Host-Only network interface ready for use!

Step 2: Attaching the New Adapter to Your VM

Now that the new adapter is available, we need to instruct the virtual machine that was throwing the error to use this new interface instead of the broken one.

1. Select the Affected VM: In the VirtualBox Manager main window, click on the virtual machine that was failing to start.
2. Open Settings: Click the Settings button (or press Ctrl + S).
3. Navigate to Network: In the sidebar menu, click on the Network category.
4. Configure Adapter 1: Ensure you are on the Adapter 1 tab.
   • Attached to: Change this setting (if necessary) to Host-Only Adapter.
   • Name: This is the most critical step! Use the dropdown menu under Name to select the new Host-Only Adapter you just created in Step 1 (e.g., VirtualBox Host-Only Ethernet Adapter #2).
5. Save Changes: Click OK to save the VM settings.

Success! Time to Test

With the new adapter created and assigned, you should now be able to start your virtual machine without encountering the dreaded VERR_INTERNAL_ERROR!

Go ahead and start your VM. Once it boots up, check its network status—you should find it successfully connecting to the Host-Only network, allowing your host machine and your VM to communicate seamlessly once again.

Dealing with networking errors can be frustrating, especially when they pop up after an unprompted Windows update. But by systematically recreating the missing component, we’ve gotten the job done!

If this tutorial saved your bacon, please give the video a Like and consider Subscribing to Darren’s Tech Tutorials for more clear, actionable guides on virtualization, Linux, and all things tech! Got questions about your specific networking setup? Drop a comment below—I read every one! Happy virtualizing!