Corrupt project: Can't add group or buss plugins / cripples other projects

Attached is a project that’s experiencing this issue. I stripped out all the tracks, except the main out (named… “Monitor Out”), for the purpose of demonstration. I’m using Cubase 10.5.20. These are some steps:

  1. Open the project. It has one master buss track.
  2. Add a third party insert plugin, or REVerence also seems to do it. Things that trigger the problem seem to be most Waves and Native Instruments plugins. iZotope stuff works fine, and most Steinberg plugins are okay.
  3. When the issue occurs, the plugin will appear and you can interact with it, but it won’t receive any signal.
  4. Try to remove the plugin. You can’t. You can’t enable it, bypass it. It appears greyed out.
  5. Now, create a brand-new project. Notice the same thing happens.
  6. Restart Cubase and create a brand-new project. Now try again, and the problem is gone!!!

Cubase Busted Plugin.png
Here’s the sample project: (CAUTION: Once you open this and try to add a plugin like above, it essentially poisons all other projects until you restart Cubase!)
Sample Nasty Plugin (581 KB)
I’m going to explore ways to export/import to maybe fix this project. It’s a real pain because I have to revert to a saved backup in order to resume working.

Also, for what it’s worth, I had a Sonarworks Reference instance in the Monitor Buss that I think I found a similar bug with, where if I enable the “Listener Spot” feature it seemed to break that plugin. I’ll experiment some more, but hopefully this minimally reproducible sample should allow the devs to inspect the project file to see what might be happening.


  • Sean


Make sure your Constrain Delay Compensation is disabled, please. Could you confirm?

WOOOOOOOOW. That was it. That must get retained when you open another project (or create a new one). I wound up copying every track (drag and drop style) to a new project to solve this.

Steinberg should make this little “feature” a little more obvious when a plugin becomes disabled. I don’t mind if a plugin is disabled when the constrain feature is on, but not being able to open or remove the plugin? No visual indicator why? Bad UI… bad.

Thanks so much! I can’t believe I missed that. (Then again, I can’t believe they would ship this feature and allow the plugin to become completely broken, rather than elegantly disabled - maybe a visual hashed through red… and a hover/tooltip indicating “plugin disabled due to ‘constrain latency blah blah’”. Would have saved me a few hours of grief.)

  • Sean