Python Error - Could not add reference to assembly ProtoGeometry

I’m using the python script & graph referenced in the following threads:

Up until today it was working beautifully, but when I tried to run the script a few minutes ago I get an error from the Python node:

Warning: IronPythonEvaluator.EvaluateIronPythonScript operation failed.
Traceback (most recent call last):
File “”, line 2, in
IOError: System.IO.IOException: Could not add reference to assembly ProtoGeometry
at IronPython.Runtime.ClrModule.AddReference(CodeContext context, String name)
at IronPython.Runtime.ClrModule.AddReference(CodeContext context, Object references)

Lines 1-3 of the script:

import clr
from Autodesk.DesignScript.Geometry import *

I’m totally lost on what to do with this one.


The error is popping up on any python node that references ProtoGeometry
revised post title.

Hi Chad,

Are you trying to use Python script in Dynamo Studio?

Not that I know of :worried:

Revit (2016) -> addins -> Dynamo

Maybe you have to reinstall Dynamo? Have you got a ProtoGeometry.dll in …\Dynamo Core\1.0 ?

1 Like

ProtoGeometry.dll is in the directory.

I’ll give reinstalling a shot.


It took a full uninstall of both Dynamo & Dynamo Core but it is working now.

Thanks for the assist! :grin:

Does anyone have an idea as to why this is happening?

I had the same issue this morning. The .dll is there but “ProtoGeometry” fails every time. I actually got the python script to run by removing those few lines. I’ll try reinstalling later.