I'm currently communicating with a user who can only get Windows8 DP8 to recognize UltraReverb when he is logged in to the admin account. Perhaps try launching DP as administrator by right-clicking on the DP executable?
I am still digging for clues about this problem.
Otherwise it could be the standard issues:
–Are you sure you installed the 64bit version?
–Do you have it in the right directory?
–Did you activate the plug-in using the iLok License Manager?
Feel free to email firstname.lastname@example.org and ask to be forwarded to Adrienne. This was we can more easily exchange screenshots etc.