Grasshopper does not recognize my surface as a plane

I’m using a script and when I plug in my plane it turns red saying “1. Data conversion failed from Surface to Plane”. and when I put in another surface it works. Does anyone know what’s wrong with this surface?

The curved one bent it wont work.

To sum up what I said, I’m not sure what’s wrong with this specific surface because if I try other ones it works

Hi Hkampin,
The automatic conversion between surface/plane only works if the surface is planar.Try evaluate surface(with reparameterize on the surface input) instead:

Thank you so much it worked

IsPlanar gives you also a plane, it’s just one component.