Lofted Boss Base - Unable to Select all Guide Curves

Hello everyone - I am having a very hard time creating a loft from a square to circle (reducer). I am using 8 guide curves in order to create transitions that will mimic the fabrication blend of a reducing pipe from a larger square cross section to a smaller circle. I manage to select 7 of the guide curves every time; when I select the 8th guide curve, the loft boss feature fails with the following error: "Rebuild Errors - Failed to reorder the guide curves." I am not sure what to do, I have tried the Boundary boss, I have tried drawing the guide curves in pairs, separately, different planes. If anyone knows a solution, I would really appreciate it. Thanks!





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