Warning PolyCurve.ByPoints operation failed. Cannot make a PolyCurve from an empty list

[Chingnamb]

Hi

I am new to dynamo and I want to use it to generate a massing model from openstreetmap. I have been getting this error but I am struggling to fix it.

The error says ‘Warning: PolyCurve.ByPoints operation failed.
Cannot make a PolyCurve from an empty list’

I have double checked the list but cannot find a nul etc. I have tried a new node but nothing.

Please help

[Nick_Boyts]

Can’t tell anything without seeing your Points output. Try using List.IsEmpty to see if you get any True values.

[luis.chambergo]

I have the same problem.

I can’t find the empty list. I tried “IsEmpty List” but it result in false. Someone can help?

Thanks

[thomasT53PF]

Seems like a @level issue, you may need to Flatten your list of points before feeeding it to the Polycurve node.