you need to convert geometry
import clr
import sys
clr.AddReference('ProtoGeometry')
from Autodesk.DesignScript.Geometry import *
clr.AddReference('RevitAPI')
import Autodesk.Revit.DB as DB
clr.AddReference('RevitServices')
import RevitServices
from RevitServices.Persistence import DocumentManager
from RevitServices.Transactions import TransactionManager
clr.AddReference('RevitNodes')
import Revit
clr.ImportExtensions(Revit.GeometryConversion)
doc = DocumentManager.Instance.CurrentDBDocument
uiapp = DocumentManager.Instance.CurrentUIApplication
app = uiapp.Application
# rest of code
for curvelist in curves:
list_rvt_curves = List[DB.Curve]()
for curve in curvelist:
list_rvt_curves.Add(curve.ToRevitType())
# rest of code
some infos here