Create new family error


I am following this tutorial to create a new family from within a project.

Everything looks like it is wired up correctly in GH but I am getting an error " 1. Grasshopper: Input parameter index [-1] too low for Component New Family."

What is causing this? I am using Revit 2021 and the latest RIR.


I got that error on the previous RiR version, upgraded and placed the newer component and it was all good. Is it an older definition?


Yep that was it. Thanks

I can add that the .rft reference file must also match the working Revit version or the WIP will crash.