Unable to union solids composed of closed breps

[Grasshope (Ji)]

I’m unable to union solids composed of closed breps as shown below.

I tried HS_Kim’s method to reconstruct each solid, yet it still doesn’t work.

The solid union is not working even if the objects are baked to Rhino.

May I ask what might be the source of this problem and what might be the solution?

Thanks.

unable to union solids.gh (93.5 KB)

[marteen.petrov]

Hi
I’ve located your problem but have no idea why it fails
The purple bois are unioned already but the blue one fails.