Problem with thin seam and layer adhesive

[rantzaus]

Hey Guys

I was printing a simple bottle/vase kind of thing, but when the print was finished the "top" of the print broke off. It was like the print did not "melt" together at this 1 layer. The rest of the print os okay, i think. Only problem is the breaking point.
I did another run, and it did the same thing, and broke at the same point.

I have attached the STL, BFB, BAK and setting files from kissslicer.

Hoping someone could help.