Hello zigzag industrial singer 457 u105 not stylist is missing stitches?

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