The issue came back and updating the Mac audio settings as much as I could didn’t help, but I do think I figured something out when testing some more. I submitted this to Slate Digital as well. I’m not sure if what’s triggering this bug is in Cubase or Slate Digital’s VMR, but here’s what I wrote back to Slate’s Support team:
I had the issue pop up again. Still not sure if this is on Slate’s side or if it’s something about how Cubase is routing audio, but I had a track I was working on, had VMR on a bass group from the very beginning and everything was running smoothly. I was working on a section without the bass playing then when I went to go back to play, the issue was there.
I don’t think the Mac Audio settings are at play - tried that trick and it didn’t work this time. However, I saved the track out to a new track that I was going to submit as a bug report and was playing around trying to see if I could get more information to help guide me to where I need to go to find a resolution, and found something interesting.
The default VMR plugin preset will still load and process the audio without any issues. As a test, I dropped a new instance of VMR in the insert chain before the problematic instance and was going to save copy of the track so I could open the Cubase track .CPR file to see if I could see what value is being affected when this bug occurs and it seems to have reset whatever audio value is causing the issue back to normal. Now my original problem track that I was working on this weekend is working fine again.
Based on my testing, what I think is happening, is when I load the VMR into the track with the default preset (Classic Strip 1), there is some value that affects the audio coming into the plugin that doesn’t change. However, when I clear that preset and try to load my own, for some reason, it’s also clearing a default input gain value for the plugin and replacing it with a much higher value when a module that uses sidechain is put into a slot. This seems to affect all input gains going to the insert channel going forward until I dropped a new instance of VMR with the default preset into an insert slot prior to the problematic version, at which point it seems to reset this value back to the default, normal value. Even after I removed that first instance of VMR with the default preset, the formerly problematic instance continued to work correctly. I don’t have sidechain enabled on this channel at all, so there shouldn’t be any other audio feeding that sidechain input from within Cubase.
In other words, it’s almost like Cubase is set up as:
Instrument Plugin → Effect Insert Gain Staging for plugins with Sidechain (this is the value that’s getting changed) → Effect Insert Plugin Sidechain Audio Input
Instrument Plugin → Standard Audio Routing → Effect Insert Plugin → Effect Insert Plugin, …, → Stereo Out Bus
When you trigger the track to record, it is muting one of those tracks, giving you the proper pre-insert track volume, but when you unarm the track for recording, it brings that doubled insert volume back up and the plugin goes silent again because it’s either phasing the audio signal since it’s being double or just becoming too loud to process any more.
I’m not entirely sure, but I did see it resolved when I put that VMR instance with the default preset into the slot prior to the problem instance/effects.
Hopefully this helps. I’m really not sure what is triggering this to suddenly break - I haven’t been able to reproduce that yet.