Use envelopes that have been stored in a dry environment.
Note: Printing on envelopes with high moisture content can seal the flaps.
Resend the print job.
Does the envelope seal when printing?
Contact customer support.
The problem is solved.
Lexmark C/XC41xx and CS/X72x: 200.13 Paper Jam Error and/or Grinding Noise when Printing
Watermarks are not appearing when printing from Google Chrome and Microsoft Edge