Sometimes the issue is caused by a dirty roller that is unable to catch the paper. To clean the roller properly, remove any paper / trays to get to the roller and paper pick up area. Use a damp paper towel with Windex or water and clean any rollers that you see big or small.
Any roller from 1 inch wide to full page width that you can see. Use your fingers to move the rollers around to clean them well.
Please let me know if you need additional help.