String breaking. I need suggestions.

[Paul WA]

Hard to say what is causing it. I ordered 2 strings (D97) from a fellow that does top notch work and one of them would not stop creeping. Upon further examination it was starting to break just above the serving, the other one on a bow with the same draw weight is still in perfect condition...PR

[big grey]

Had this happen twice to me,both times with dacron strings.Strings had two color bundles black and white,yellow and black. Yellow and white both snapped half way between serving and string nock lower limb.Both strings had stretched about 1" before snapping I know this as I had reset brace height with bow square.
Strings were bought at the same time 14 years ago,one had snapped 14 years ago. The next broke this week.Brought bow out retirement,replace string out of packet. Maybe rotten dacron ?