Hello Tania,
This is Sebastian from Customer Support at Weta Tools. I'm sorry you are experiencing these issues with Ziva VFX.
Since this is out of my technical scope, I asked directly with one of our developers and this is the answer I received:
"It seems like the issue the user is facing is unique to their situation. By examining their file, one should be able to identify the problem. Based on the description, it's possible that the curve in question might have multiple shapes (e.g., shapeOrig), but this is just an assumption until we can take a look at the actual file.
When using the "create-line-of-action" command to generate a curve, it creates a linear curve with 2 control vertices (cv's), using the endpoint weight of zfiber as a reference. It doesn't automatically create multiple cvs; the user needs to manually create them and then use zRivet, which requires both a cv and a zbone object, to make it work.
This command will give error as command requires to select geo and curves :
looking at the image it has selected some group node, again its just looking image i m assuming it. but actual file can give full story.
2nd image selection right but second object is a group node than the geo .. but somehow it worked"
Based on this, please try the solution described above. If this does not work, kindly your file via our already-placed Support ticket.
Thank you!