I’m getting the same error. The initial connection to Twinmotion from Revit worked fine but once I made a minor edit and tried to Sync it gave me this error. I didn’t add any additional geometry, just edited a ceiling and reloaded. I am using a Revit site model that has the building model linked into it so I’m wondering if that is causing the issue because I haven’t seen this type of error before when syncing a building model directly to TM. I’m using Revit 2025.4 and Twinmotion 2024.1