I'm using Reason 11, and as far as I can tell, plug-ins must be VST2, not VST3. I think NI is installing the instruments I'm trying to use as VST3s, because Reason is not recognizing them.
A lot of the more recently updated NI plugins are VST3 only unfortunately. You could try using something like BlueCat Patchwork which runs as a VST but hosts VST3 plugins internally. It's not ideal, but it's a workaround - Blue Cat's PatchWork - Fully Configurable Plug-Ins Chainer and Multi FX / Standalone Host or Plug-In (bluecataudio.com)
Not that much cheaper than the current £99 upgrade price for Reason though.
-- Mike
Thanks for the advice. I upgraded to Reason 12 in order to be able to use VST3s, but I still can't get them to work. I loaded Kontakt and Kontakt 7 successfully, and they will install as instruments in my project. But when I try to load a patch into them, the instrument VST file folders appear, but the "instruments" subfolder is empty, and I can't find anything loadable in any of the subfolders.
Have you run Kontakt as a standalone app first? If not give that a go. If you've done that do you see all the patches and can you load them?
Yes, I can run it as a standalone and the instruments appear and work properly. Still no joy inside Reason, though.
I ran explorer and discovered that the instrument nki file is present in the Content folder, but the Reason Browser doesn't show the file when I open that folder. I tried dragging the nki file into Kontakt and Reactor (inside the Reason project), but got the error message that the file type is not supported.
If you are on Mac have you given Reason full disk access?
Sorry, I should have said earlier, I'm on a PC running Windows 10.