I am having the same problems. The “Add VST Plug-in Picture to Media Rack” option is not showing up for both Spectrasonics Trilian nor Stylus RMX. I am not sure I understand your steps that you did to get the picture saved. Can you please clarify? I am a new user Cubase (1 week). Did you submit an actual bug ticket to Steinberg? If not, do you want me to do so?
Trying to get the picture from your steps below, but not fully understanding. Is this from the VST rack or from the track selection, etc? Not clear. Thanks.
Also, the Trilian picture and function menus appear after loading, followed by closing the interface, then re-opening with the Edit Instrument icon.