It is possible that Minishift config contains the wrong data. Reasons can be many, one of them is that the VM got deleted via VirtualBox GUI and thus the Minishift has data about VM which does not exist. During the startup Minishift then asks for the status of VM, but VirtualBox cannot provide any information about it as it does not exist. So you need to delete the folders from your windows system. You can use the below command.
$ minishift delete --clear-cache