I believe this is something we need to debug, probably an exception thrown by the Revit API.
Can you please upload a sample model to this secure folder I just shared with you?
Please confirm the version of the Revit Connector and Revit file you have been using.
Lastly, also reply here with instructions on how to reproduce it, and we’ll look into it.
Since the link to Google drive is not working, I just sent the sharepoint link to Matteo Cominetti matteo@speckle.systems. Please check and let me know if you need anything else.