The label sheet is facing the wrong way in the tray.
Labels are missing, curled, or pulled away from the backing sheet.
Do not use any sheet where labels are missing, curled, or pulled away from the backing sheet.
Envelopes are loaded incorrectly.
You can print envelopes from the Bypass Tray or Tray 1. For more information, refer to Guidelines for Printing on Labels and Envelopes
Envelopes are wrinkling.
Note: When you load envelopes long-edge feed, ensure that you specify landscape orientation in the print driver.