"Sorry, Plug-in Effects cannot be performed..." notice

I need to finish a project by Friday and ran into a major problem while mixing down a project. Whe attempting to add reverb to a track, I get the following message:

“Sorry, Plug-in Effects cannot be performed on stereo tracks where the individual channels of the track do notch match.”

I changed the track to mono and exported it as a WAV file. When I imported the audio file as a mono, I still get the message and can’t apply any effects.

Is there a way to resolve this problem?

Whose reverb? The Audacity built-in one? Does it work on any one of the other tracks?

Describe briefly the show. How many tracks do you have and where did the work come from? Are you mixing down a production built around a rock concert capture and interview? Are you building a show out of “Found Work” which seems to be in fashion?


Try selecting the track, then “Tracks menu > Mix and Render”. This will “render” the track to the current project rate and place the track at the bottom, below any other tracks. Then apply the Reverb effect.

Thanks for the kind responses.

I was using Gverb. I was unable to apply any effects to any of the tracks.

Sorry, but I panicked with tomorrow the deadline to finish the mix-down. I exported each track as a wav file and copied them to another PC, where I rebuilt the project. I then deleted the old *.aup and data files. Once I transferred them back to my main PC, I was able to apply the VST effects.

But I made a note of what you shared.

Wish I knew what I did to cause the problem. I was doing a lot of mix & rendering.

Again, Thanks. You folks are great.

If you had some tracks at different sample rates and did “Make Stereo Track” on the Track Drop-Down Menu, that does not do a render, just attaches the upper track to the lower track, leaving a stereo pair with the channels at different rates. That would cause the issue in GVerb, but exporting should have made both channels take the project rate you exported at. Perhaps you still had other stereo tracks that were mixed rate?