Karamba Mesh Limit?

Hello! 

I'm Working on a karamba model of a multi-pavement building, with shear walls and floor shells as a structure...

What's happening is: I've sucessfully modelled one pavement, making sure every shell is connected and there are no free rigid-body motions. But, whenever i try to "Copy" it for the 11 pavements the building actually is, I can only go up to the fourth pavement, after that it says i have an unstable frame.

For me, it doesn't make much sense, since it's a slider varying from 4 to 11, if it works for the first ones, should work for the rest.

Is there a node/mesh limit on karamba?

Any idea how i could work this around?

Thank you!