Unable to unite Splines using Boolean operation "Union"

[vankish]

I have multiple splines. I attached them all together. I try to perform the Boolean operation "Union" so they get joined together. Nothing happens. The splines still won't share any vertices.

What am i doing wrong?

I have 3 circles and many lines which are all different splines. I need them all to be a single spline.

I'll leave the .max project attached. This is my first time in years asking for help online instead of solving it by myself but i have tried everything and i'm going crazy 🤠

[RobH2]

Without knowing what you are trying to do with it I may not be grasping the issue properly but it's already one spline. You have some coincident vertices. By doing a 'Weld' you reduce those and then you can just 'Trim' to do about anything you want with it. I made a video in case it helps. 

If it's sitll not working explain a bit more what you are trying to do so I can understand better. 

[Diffus3d]

Maybe they are instanced?  What happens if you un-instance them?  (If they are indeed, instanced.) 

Best Regards,