TOPIC: Window Defects??

The food source I believe would have had to occur during the manufacturing process, during which the inside of the glass got contaminated, the moisture would have most likely came from seal failures, which allowed condensation to occur last winter??
The HO was not aware of more than just  the  one window that condensated.

I was not able to get back today, but when I do I will look at the outer panes for these markings also

I have seen numerous stress cracks in the glass, caused by the pane being installed incorrectly in the frame.

If incorrect installation is causing stress cracks then couldn't it easily cause the seal to break and moisture to get in as well?

I have seen numerous stress cracks in the glass, caused by the pane being installed incorrectly in the frame.

If incorrect installation is causing stress cracks then couldn't it easily cause the seal to break and moisture to get in as well?

Yes, but the tail tale sign of a stress crack is a crack that starts in the corner of the sash, which is very noticeable, there are none in the windows in question. when the weather breaks and they start replacing, I will get a couple and split the panes and do further investigating

I have seen numerous stress cracks in the glass, caused by the pane being installed incorrectly in the frame.

If incorrect installation is causing stress cracks then couldn't it easily cause the seal to break and moisture to get in as well?

I should have added that the incorrect installation is when the sash frame is too tight for the glass, and the crack is caused by the expansion and contraction of the vinyl