Note the following points to scan documents.
"Mis-feeding (multi-feed)" errors are usually caused by dirty or worn pads. Clean the automatic feeding area, following the procedures outlined in the Operator's Guide.
Fan the document
1) Take a stack of documents that is less than 5mm thick. (50 or less general office sheets.)
2) Hold onto both ends of the documents and fan them 2 or 3 times.
Pull the paper chute guide and its extension out of the paper chute.
Align the edges of the documents in a step-like pattern (see picture below).
Load the documents within the scale that is inscribed inside of side guide.
Adjust the side guides so that they meet the width of the documents that are about to be scanned.
Adjust these side guides so that there is no gap between the side guide and the document edges. If there is a gap, it may cause skewing of the document during scanning.
Place documents so that the leading edge becomes the trailing edge.
Place documents that have a narrow margin between printed text and leading edges or documents containing staple perforations so that the staple holes and / or narrow margins face upwards.
Pad ASSY (PA03586-0002, replacement cycle: 50,000 sheets or 1 year)
Pick Roller (PA03586-0001, replacement cycle: 100,000 sheets or 1 year)
Confirm whether ScanSnap supports the document size.
Refer to "Q5. What document sizes can I scan with ScanSnap?".