Seems to be failing all the time, and when I try processing a ProRes file, Hybrid quits as soon as I add it.
Assuming you didn't add a new virus scanner or similar that is running amok,..
Try deinstalling Hybrid with settings and reinstalling it.
Also check that no global Vapoursynth is installed on your system.
I've already tried re-installing twice. Windows 10 ran an update yesterday. Could that be it?
Can't really say whether a Windows Update could be the culprit (not using Win10 here).
Does it change anything if you tell Hybrid to use Bestsource?
Where do I find the Bestsource setting?
Filtering->Vapoursynth->Misc->Source has options for source filters,..
But that probably will not help if for some reason Vapoursynth itself doesn't work properly.
More likely some antivirus program or similar running amok.
I just managed to load a ProRes file, but the preview window still only displays grey.
If you see a grey window only, keep it open, open an vsViewer through Tools->vsViewer and press F5, that hopefully shows an error message,..
I haven't installled any anti-virus software. It's a mystery.
Hmm,.. I have Windows Defender and Malware Bytes here, but in both I got exceptions for the Hybrid folder,...