Someone with a DK1 mentioned earlier that he had to uninstall the Oculus runtime, then remove the Oculus folder from the program directory completely before reinstallig the latest runtime again to make his DK1 work with vorpX 0.7.5.
I’m not sure why that may be necessary, but it’s worth a try. Make sure to re-boot before reinstalling the runtime.
If that doesn’t help, please send a mail to support |at| vorpx com to receive a downgrade option to a pre-DK2 version of vorpX, which does not rely on the Oculus runtime.