Posted an issue on the Cubase 11 main site, but had no responses - but it may be best placed here (admin please advise if not the case?).
When I drag layers e.g. unmixed vocal stems into the Cubase project window, I get an “error message: Medium type not supported or invalid medium”. I have tried different file types, MP3, WAV etc but issue persists. I did previously have a trial version of Spectral Layers 7 Pro, so not sure if that has anything to do with it however, the correct version of Spectral Layers One with latest build is present in the editor window.
I have since found an effective workaround using render-in place.
Not sure if this is specific to my set-up (OS Mojave 10.14.6) and if so, likely fix or is more a general issue?
PS. Spectral Layers is a v.powerful tool, particularly the un-mix tools - I have RX8 - and Spectral Layers is more effective and prefer its non-destructive / layering way of working. So will look to take advantage of the cross-grade offer for the Pro version at some point in the near future.