A possible cause may be that paper is not loaded properly or appropriate paper is not used. Check the following.
Is paper loaded correctly?
If paper is not loaded below the load limit line or is loaded obliquely, it may crease. Loading Paper
Are you using paper that has absorbed moisture?
Does this problem occur when printing on plain paper or thin paper?
Change the setting for <Paper Wrinkle Correction>. Setting to <On> may solve the problem. <Adjust Image Quality>
NOTE
If you set to <On>, the print may be faded or the printing speed may be slower.
Are you using appropriate paper?
Check usable paper, and replace with appropriate paper.
