Error Alert when attempting to play song

I click “play”. I get an error message that says: “Error instantiating plugin”. The file won’t play. What does this mean and how do I fix it?

Is this a recently created song or an old one? Are you using the latest or an older version of n-Track, which one? Which effects does the song use? Perhaps the song uses some 3rd party effects that are not currently installed. Missing effects should appear in red in the mixer. If this doesn’t help try saving a backup copy of the song, then remove effects until you see the message disappear, so that you have then identified the problematic plugin, and you can make sure that it is installed correctly.