On rare occasions, Cubase/Nuendo forgets already set up audio devices after being restarted. In these cases, you need to re-select the affected audio interface in the startup dialog each time they start Cubase/Nuendo.
A potential cause for this behavior could be e.g. a Thunderbolt hub (like the OWC Thunderbolt 3 hub) that is known to provide a new hardware ID for the built-in audio device on every cold start.
This new ID makes the audio interface selection dialog comes up every time.
Since Cubase 9.5.40/Nuendo 8.3, it is possible to work around this issue by placing an audio interface blacklist in Cubase's/Nuendo's preferences folder. Blacklisted devices will then be ignored by Cubase/Nuendo on startup, preventing the selection dialog to reappear.
Here's how to blacklist audio devices in detail:
- Quit Cubase/Nuendo.
- Create a text file using Text Edit or another plain text editor (for example, TextWrangler).
- List all unwanted audio devices that should be ignored when CoreAudio2ASIO is initialized - one device per line. Only leave the desired audio interface unlisted.
- The names of the blacklisted audio devices must be typed exactly as shown in the audio interface selection dialog. In the case of the OWC Thunderbolt hub example, it would be:
OWC Thunderbolt 3 Audio Device
- Save the text file as ignoreaudiodevice.txt under: ~/Library/Preferences/CA2ASIO/
- Start Cubase/Nuendo.
If all alternative audio interfaces have been blacklisted correctly, Cubase/Nuendo will automatically connect to the requested audio interface.