I think maybe the catch is with the Full version of AC3Filter you may need to register the 32-bit version by hand, or maybe you need to make a selection during the install. I'm not sure, since I don't run 64-bit here. But yes, installing the Lite version obviously takes care of that, since it's 32-bit only.
server: NextPVR 5.0.7/Win10 2004/64-bit/AMD A6-7400k/hvr-2250 & hvr-1250/Winegard Flatwave antenna/Schedules Direct main client: NextPVR 5.0.7 Desktop Client; LG 50UH5500 WebOS 3.0 TV