Is a document jammed inside the ScanSnap?
Remove the jammed document, and perform scanning again.
For details, refer to Removing a jammed document.
Have you scanned a document whose length exceeds the maximum length that can be scanned with the ScanSnap?
There is a limit on the length of a document that can be scanned with the ScanSnap.
For details about the length of a document that can be scanned, refer to ScanSnap Help.
Is the top cover open?
Remove the document that you are scanning, and close the top cover .
If none of the above is applicable, close the feed guide of the ScanSnap to turn it off, and open the feed guide again to turn it on, and then perform scanning again.
Make sure that you leave at least 5 seconds between turning it off and on.