Here is my whitelist:
Superior Drummer 3
Kontatk 5 16out
Here is my Kontakt installation path:
C:\Program Files\Native Instruments\VSTPlugins 64 bit
I suspect the issue isn’t the whitelist since Kontakt worked fine for Dorico 2 without explicit whitelisting. I am going to try moving the Kontakt dll into a path Dorico 3 is already searching, since the likely real issue here is that Dorico 3 doesn’t honor new VST paths when set (they are reset back to the defaults on restart).
Diagnostic report can be downloaded here (was too big to attach to forum): https://1drv.ms/u/s!AkJKS0bhzKxZrXTNnONLe3yEXu0K?e=IFwyo9