PolyBeam from PolyCurve

Hi, am very new to Dynamo and trying to complete something from scratch using an Advance Steel PolyBeam, if I try this with a straight beam it works, I can’t find any examples of the use of PolyBeams in the examples provided by Autodesk. Wher am I going wrong?

Je pense que vous devez mettre True (Boolean) on ConnectLastToFirst to make it work. C’est la seule solution que j’ai pu trouver malheureusement.

Thankyou for the reply, it does work as you say, it seems the PolyBeam must be closed, a bit limiting.