Thanks for the data. This is all totally weird. According to the latest log it said:
2019-09-06 10:35:51 : Plugin refused: Komplete Kontrol.dll
2019-09-06 10:35:51 : Plugin accepted: Kontakt 5 16out.dll
2019-09-06 10:35:54 : Plugin refused: Kontakt 5 8out.dll
2019-09-06 10:35:54 : Plugin refused: Kontakt 5.dll
2019-09-06 10:35:54 : Plugin accepted: Kontakt.dll
So Kontakt and Kontakt 5 16out got accepted. Why does it not turn up in the list of instruments in Dorico then?
Can we try something different then. You say it works in Dorico 2.
Under AppData/Roaming/Steinberg is also a VSTAudioEngine2_64 folder. If you go into that one and delete the Module Cache.xml file and then start Dorico 2, does Kontakt still get recognized by Dorico or also blacklisted?
In 99% of all cases, when a plug-in gets blacklisted, then because it is crashing in the vstscanner. This is an additional program that acts as a safeguard. It tries to load all plug-ins once and sort those out that make trouble, so that the audio engine later only meets well behaved plug-ins.
This is all so weird, I propose we do a TeamViewer session next week, where I can see your desktop and see myself. In what timezone do you live?