You may need to download and install the latest Wibu-Key driver. You
can do so by navigating to the link below and selecting the appropriate
download under the “Wibu-Key for Users” section:
http://www.wibu.com/downloads-user-software.html
Please also confirm that you have downloaded the appropriate version of V-Ray, as 32 & 64 bit versions will not work concurrently. If you have a firewall enabled, try disabling it temporarily as it may be preventing the connection between V-Ray and the dongle.