Dux-Soup does not recognize my file format
In order for "Revisit Data" to work, make sure your document is saved as a CSV.
You can do that by clicking on File > Save As... on your Excel
Then save it as a CSV
If you uploaded the file but are still getting error messages stating the file format cannot be recognized, try reloading the extension. You can do that by going to Options > User tab and hit "Reload Configuration", then upload your file again.