I re-installed my Mac Mini and have tried both Vienna Instruments 6.0.16999 and Vienna Instruments Pro 2.4.17181 (Trial), and I can't get neither of them to show up in Logic.
I'm on Mojave 10.14.3, and Logic 10.4.4.
Any clues? I would like to open my old projects, which use Vienna Instruments, and continue to use the libraries I've paid for.