Can't Delete Unused VST's

Sometimes I cannot delete unused VST’s.
I got an error thrown by an unused instance of Kontakt this AM (probably a Kontakt loading issue of some kind), and I figured to just get rid of the instance.

There’s a little garbage can icon in Play>VST and MIDI, that looks like it should be able to delete a VST instance. Nope, only sometimes. When working with Cantai I found it could work only after selecting “–” at the top of the list. Today, an instance that had contained Kontakt 8 won’t delete - and it’s not being used anywhere, and won’t be deleted even after selecting the null instrument. The garbage can is greyed out when the slot is selected and doesn’t work. What might be happening here?

if the VST is not in the last slot (which I assume is your situation), you can’t delete it.

Thank you for taking the time to reveal this undocumented (?) information here.
If it is documented, I would like to be able to read about it. Is it documented anywhere?
A search of the Help for “delete VST” doesn’t reveal this particular condition.
In the meantime, the means to do so appears to have been provided. What you say makes sense, when allowing for the possibility that VSTs have ordinal ID’s under the hood, and updating all those links would take a lot of code.
Meanwhile, now that I know, I won’t waste any more time trying to do something that looks like it should work.

I’m not sure if it is officially documented, but there have been numerous threads discussing this if you care to search.

It is caused by the separation of the VST audio engine from Dorico and the communication between the two.

Hey @jonburr

I can vouch for what @derAbgang said: it has to be the last VST entry otherwise you cannot delete it.

Shore

It sure would be nice if we could delete instances out of that order. It would also be nice if we could copy and paste Inserts/Effects as well. Mostly, the latter, because not all VSTs cooperate or use FX that, I thought, was to affect all instruments across the board but I may have just dreamed that…

Have you tried reapplying a Playback Template?