-- Starting Minishift VM ..... FAIL E0321 11:29:07.578030  

21298 start.go:494] Error starting the VM: Error creating the VM. Error with pre-create check: "Error detecting VBox version: exit status 126". Retrying.  
Error starting the VM: Error creating the VM. Error with pre-create check: "Error detecting VBox version: exit status 126"  

I got the above error while firing up Minishift to run through Rafaele Benevides Istio Tutorial for Red Hat Developers, which you can find here:  https://github.com/redhat-developer-demos/istio-tutorial

The error is related to an incomplete uninstall of Virtual Box.  The solution is simple: download Virtual Box and run the Uninstall Tool.