Hello, I am trying to generate a structured hexahedral mesh on a Swept Fibre Geometry along  wire splines(in total 5). I partition the circular cross-section faces of each spline and then i partition the volume cells by sweep partitioning approach .

In 4 out of 5 cases i am able to successfully sweep the partition, but in the fifth spline it does not allow me to sweep the partition(cell) and asks me to choose another strategy .I am attaching with this query the photograph of my model'

I create the face partition in the top view and sweep it towards the bottom face for partitioning the cell.The green splines are the ones with successful partiton. Leftmost fibre has the sweeping problems.Top View image has the face partioned i.e is to be swept and Bottom view shows the partition that is successfully executed. Is there anyway to carry out the sweep partition . I tried to explain the problem as concisely as possible please let me know if there i can supply any additional information in case of lack of completeness of the descriptiom Thanks in Advance