Originally posted by Aaron28 honestly i do not know! i am very new to this.....however there have been times when a very distinct magenta bar (maybe twice the width) has been caused by dust and there is certainly dust in the scan (solid yellow squigs) so it maybe due to my "messiness".......there are other lines which are much smaller in width that i believe is the film......
I don't know what scanner you're using but my Epson v600 does that from time to time, sometimes starting in the middle of a roll. I try to watch for it during the scan, and the only way to get rid of it I've found is restarting the scanner and redoing the scan(s).
Sometimes the streak can be cloned out in post in individual shots, but generally not worth the effort.