Cubase 12 Pro Stopped Processing External Audio

OK, here’s a weird one. I’ve spent the last 4 hours trying to figure this out and I just can’t.

I’m running C12Pro (fully licensed and updated) and today, in the middle of a session, Cubase stopped processing external audio.

I’m an advanced user. Been using Cubase since SX3. I have C11.5 Pro and Ableton Live 10 on my computer and both continue to work properly, only C12 has stopped working.

W11Pro 22H2
Custom DAW i7/12700 on a Z690
64 gigs of DDR5
3 NVME drives, and 3 SSDs.
RME UFX+ interface old 2 old MR816s running as ADAT sources.

When playing external audio, I see deflection on the RME Totalmix mixer (so I now audio is coming in), the input channel meter in C12 (so I know the interface is properly routed in C12), and the individual audio channel meter in C12 so it appears the input channel is geting routed to the audio track. But there is no audio in the graph in the track’s channel settings equalizer window and no audio is getting out of the track to the two buss or the Control Room. No audio at all…

Here’s the really weird part; it still processes midi, plays VSTis correctly and the metronome still works (so the audio from non-audio tracks is getting to the 2 Buss and the Control Room); but no audio coming from outside is getting processed inside Cubase.

I’ve uninstalled and reinstalled it and it still doesn’t work.

It literally just stopped working in the middle of a session and I can’t figure out what happened. No power spikes or surges; just up and died all on its own.

Like I said, C11.5 and Live 10 both continue to work properly on my DAW, so it’s definitely a C12 issue.

I just sent an email to Support, but who knows if or when I’ll hear back., so any thoughts or suggestions would be appreciated.


Is the Monitor enabled on the Audio Track, please?