08.07.2020, 18:31
On my fresh Windows install of the 2020.06.21.1 version I tracked this down to the Vapoursynth script trying to load neo-fft3d.dll (although I don't think I was using it), but the /64bit/vsfilters/DenoiseFilter/NEO_FFT3DFilter did not exist. When I manually added the folder and file I then had havsfunc (for QTGMC) fail at line 1258 because it was trying to load FFT3DFilter, which was not being loaded in the Vapoursynth script. So Under Filtering > Vapoursynth > Custom I added a core.std.LoadPlugin command to load the /64bit/vsfilters/DenoiseFilter/FFT3DFilter/fft3dfilter.dll plugin. Then the encoder ran fine with the Vapoursynth processing.