Curve.Length Error: Asked to convert non-convertible types

Dear Community

I have an Error occuring at the"Curve.Length", when i try to calculate the length from delaunay surface. When I run it in my some project, this script runs smoothly, but when i try in another project this message appear.
Thank you for your Help


Im pretty sure if you check your list of analysis grid, you have a null value somewhere so the Curve.Length node is outputting an error.


i’ve checked manually and also checked with “list.clean” script, and i didnt found any null data

can you provide the script and a sample revit file?

there are the script and my revit file

Hi @farhanardianzaf
filter out the value that cause the problem or use

Hi @paris, i am new to this thing, and i don’t know what you mean. Can you please explain to me

Try using an Object.Type node after your codeblock for the analysis grid and then a List.UniqueItems, and preview the results. If any of those object types don’t have a valid length.

1 Like

Hi @farhanardianzaf can you show the error of your node “Curve.Length” and the image of your graph? check also the output of “Curve.Length” node like this:


1 Like

Sorry @jacob.small I don’t see your post before…

1 Like

No worries! The visual is likely more helpful here. :slight_smile:

thanks for the help @jacob.small @blsalvio @paris