I’ve changed the location of the vst2whitelist.txt and changed the file: remove only the numbers. This works!!
Kontakt 5 16out
ARIA Player VST Multi
VST 2.x plug-ins. The process of whitelisting VST 2.x plug-ins so that they can be used with Dorico has been simplified. Firstly, in addition to the default vst2whitelist.txt file that is included with your Dorico installation, listing those VST 2.x plug-ins that Steinberg have qualified for use with Dorico, a second vst2whitelist.txt file can now be loaded from a user-specific location that will not be overwritten if you subsequently update or reinstall Dorico. When Dorico starts up, it reads both the default whitelist file and your user-specific whitelist file to build up the list of whitelisted plug-ins.
If you want to whitelist any VST 2.x plug-ins that are not included on the default whitelist, you should place your own vst2whitelist.txt file here:
Win: C:\Users\username\AppData\Roaming\Steinberg\VSTAudioEngine_64 Mac: /Users/username/Library/Preferences/VSTAudioEngine
Secondly, the vst2whitelist.txt file now need contain only the filename of the VST plug-in to be whitelisted, minus its file extension (.dll on Windows and .vst on Mac), with the name of each plug-in on its own line in the text file.