Make sure you have selected either Office Mode or Professional Mode in Epson Scan. See Changing the Scan Mode for instructions.
Make sure Auto Detect (Office Mode only) or ADF is selected as the Document Source setting in Epson Scan. See Scanning in Office Mode Using the ADF or Scanning in Professional Mode Using the ADF for instructions.
If the ADF is open, close it and try scanning again.
If pages remain inside the ADF, open the ADF and remove any pages from the document table. Then look to see if paper is extending from either end of the feeder.
If pages still remain, follow these steps.