Complication with USB drive as a bootable drive for my virtual machine

I wanted to use a standard 16 GB Sandisk USB drive as a hard disk for my VirtualBox machine to be running Ubuntu. I allowed read-write access and all the required permissions and used the VirtualBox command to make a virtual hard disk image. It accepted the vmdk and it opened up the window when I clicked start, but it failed. This was the error:

Failed to open a session for the virtual machine Linux.

Apologies for the random naming of the vmdk.

VD: error VERR_NOT_SUPPORTED opening image file '/Users/Vishisht/coolio.vmdk' (VERR_NOT_SUPPORTED).


VD: error VERR_ACCESS_DENIED opening image file '/Users/Vishisht/coolio.vmdk' (VERR_ACCESS_DENIED).

Failed to open image '/Users/Vishisht/coolio.vmdk' in read-write mode (VERR_ACCESS_DENIED).

AHCI: Failed to attach drive to Port1 (VERR_ACCESS_DENIED).

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

I used SATA Port 1, so it could boot from the USB first and not my original SSD in my macbook.