1. Remove old plug-ins and re-install the correct plug-in
1.1: If you already installed the correct plug-in and you encounter problems while exporting your model or while using the LiveSync function, please follow step 2.1 to 2.3 in this article:
Download Link: Download Lumion LiveSync for Revit
1.2: Then install the latest plug-in at the top of that article, start Revit and click on the Help button (Lumion logo) on the Lumion ribbon in Revit, and make sure that it matches the version you downloaded:
Once you've verified that it is the correct version, you should be able to export your Revit models to Lumion with the plug-in.
Please note that the LiveSync function requires Lumion 8.3 or newer and the latest version of the Lumion LiveSync for Revit plug-in.
1.3: If this does not resolve the problem, please follow these instructions:
Knowledge Base: How do you get help with import/export questions?