Not sure if this is exactly the right place but...
When creating a sketch pattern feature in a part document.
If you select a seed point, that is itself a sketch point (in the patern sketch), the feature being patterned is duplicated at the seed point.
I ran into this problem, as a sketch driven pattern feature would not suceed.
I could make a linear pattern feature from the loft cut loft features, but not as a sketch driven pattern.
I found a solution after deleting the seed sketch-point in the sketch used for the pattern.
This was not ideal as now the driving sketch which also used patterns had some under defined sketch points.
I inserted a construction line to define the sketch pattern seed point, so SW would not try to re-create the feature at this position.
(please see the picture, and my thoughts as to a great simple solution for this problem...)
What a pain… I’m sure I am not the only one who has this kind of thing happen to them.