Can also confirm on Windows 7. Can also confirm that even when you do finally get your synth devices recognised again using the Midi Device Manager, an Export - Import under Cubase 9 still exhibits the same ‘Midi Device’ behavior as mentioned by “The Elf”.
Very disappointing as I spent many (many) hours manually editing midi_device.txt files so all my external synths and expansion cards had all patches mapped within Cubase
Temporary Fix: If you still have them, copy your edited synth_patch.txt files into the %appdata%/Roaming/Steinberg/Cubase9_64/Scripts/Patchnames folder (See attached image). On startup Cub9 adds the synth_patch.txt files to the list of possible Midi Devices you can install under the “Install Device / Add Midi device” menu. At least then you can re-add your devices under the Midi Device Manager and re-map corresponding midi in/out’s.
If you no longer have the synth_patch.txt files… it’s a world of pain editing new ones… Sorry.
