When trying to run a report you get the below error message.
The above error is thrown when a sheet was added to the Cosmos report before the Cosmos Add-in loaded. When the report gets run the Cosmos Add-in doesn't recognize it and then throws an error.
To resolve the error, the user will want to duplicate the sheet or sheets that were added. Then delete the original sheets. Finally rename the copied sheets back to the original names.
If there were Excel Links on any of the sheets that were deleted, those links will need to be remapped to the newly duplicated sheet. If you open the Excel Links tab in the Task Pane, any links that are highlighted in red will need to be remapped.