VirtualBox fails to attach driver when starting VM

Question

I have three VirtualBox VMs on my Windows 10 host, one Linux Mint 17.3 and two Ubuntu 14.04.4. Often when I start any of the VMs I get the following error message at launch:

Failed to open a session for the virtual machine Mint.

Details:

Failed to open image 'D:\OneDrive\VMs\Mint.vdi' for writing due to wrong permissions (VERR_VD_IMAGE_READ_ONLY).

Failed to attach driver below us! Image is read-only.
(VERR_VD_IMAGE_READ_ONLY).

AHCI: Failed to attach drive to Port0
(VERR_VD_IMAGE_READ_ONLY).

Result Code: E_FAIL (0x80004005)
Component: ConsoleWrap
Interface: IConsole {872da645-4a9b-1727-bee2-5585105b9eed}

This is temporarily solved by using the VirtualBox installer to repair the install. Though the problem occurs again after a few launches of VMs.

What else can I do?

Answer 1

Having the VM files in OneDrive folder can cause this error. Temporarily stopping OneDrive when opening VMs solves this issue.

Answer 2

Sometime this error appears in case something wrong with VB drivers themselves.

If you can't start ANY virtual machine try to reinstall/upgrade VirtualBox.

Answer 3

If this is the file path in the error message (as in OP's error): 'D:\OneDrive\VMs\Mint.vdi'

1. Navigate to that folder
2. Try to change the extension of the file (e.g. change vdi to vdi2)
3. Take note of the error message that appears

In my case, Backblaze was trying to upload the file to the cloud and locked it, which was causing the error. I only discovered by trying the steps and getting the error message "This file is locked by Backblaze". I assume the same thing happened to OP, only with OneDrive.