This error could have occured due to the Hyper-V enabled in your system which is blocking the Virtual Box and please note that this error is not related to the Denodo QuickStart Virtual Machine.
Mostly, if you would have installed docker in you system then the Virtual Box will stop working due to the the Hyper V enabled. In order to overcome this issue, you could disable the Hyper V and then try again to start the Virtual Machine. Besides that, you could also ensure that correct virtualization options are enabled in the BIOS in the Virtual Box.
Hope this helps!