[Windows/macOS] A "Documents have been loaded in the ADF paper chute (cover) and inserted into the manual feeder at the same time." message is displayed

Has a document been left in the manual feeder?

Check that there are no small pieces of paper left in the manual feeder .

Remove unnecessary documents, load documents in the ADF paper chute (cover) or insert a document into the manual feeder, and then perform a scan.