This may be basic but not unusual is the needle in the wrong way round
ixtis
March 2017
first thing you can try is to remove needle plate and clean around hook area sometimes its just because of fluff that stitches are skipped also when last was needle changed if that doesnt help you will have to check tension and lastly timing
johan
February 2017
I can answer this question...
Hello zigzag industrial singer 457 u105 not stylist is missing stitches?