Daniel, this is the first message to be read when it comes to getting VST2 PlugIns to work with Dorico.
It does link to an outdated Knowledge Base article which has some wrong information still and might cause trouble.
It still shows the name of the whitelist text file as whitelist.txt - which will not work in Dorico 2
[edit] ah I have just seen, the article has been updated! Thank you.