If you open Sunday Keys and you receive an error message that Sampler Instrument Worship Pad.exs or Wonderful Pad.exs is missing, MainStage is having trouble locating these custom sampled patches that were included in Sunday Keys Version 2020.
In the video below, you'll see how to reveal these samples (or how to make a concert file smaller). Sunday Keys 2020 had these samples "baked" into the concert file, so they are tricky to locate at first.
From there, you'll be able to tell MainStage where to find them.
You might also consider a fresh download or upgrading to the newest version of Sunday Keys. If you'd like to do that, just reach out to us here for more information.