If you uninstall it, remove the registry key using the following method and reinstall, do you have the udatasmith export format back ?
- go in the registry editor, use the Edit > Find tool and write down the name of the plugin as stated in the Apps and Feature / Remove programs management window of Windows. In the case of 3dsMax it will be Unreal Datasmith Exporter for 3ds Max. Press “Find Next”.
2.After a few seconds you will be presented with a list of Registry Keys. Select the associated Registry Key folder on the left and delete it.
To verify you have deleted the right Key, you can do step 1. again : if it doesnt find any entry after a few seconds, you’re good to go on that end.3.To be sure to clean everything correctly before installing again, you can also delete the UnrealDatasmithMax folder located in C:\ProgramData\Autodesk\ApplicationPlugins