This is caused by using the wrong check stock or paper with the wrong check style design or vice versa.
For example, if you have designed a check #8100 and experience this issue, then you are trying to print a #8100 style check design on #8000 stock. If you experience this issue using #8000 design, then you are trying to print a #8000 style check design on #8100 check stock.
Be sure that if you have designed a #8000 style check, that you print on #8000 check stock paper.
If you have designed a #8100 style check, that you print on #8100 check stock paper.