Edge Rounding issues

 From:  F.ip2 (CEKUHNEN)
6410.1 
Hello there,

Moi does not want to round/fillet the edges of the middle and right chair. The left chair works well.

Thus I rebuild the side surfaces with a rail command but still the two chairs have something MOI does not like.

Any idea where the flaw in the geometry could be?


I can only round the edges in Rhino as you can see in the screenshot.


Thanks

Claas