franchais Hi! Its interesting that you see this popup as it shouldnt be seen with twinmotion plugin. This popup should open only in case you are exporting udatasmith file as RN supports UE export. However as far as I know Twinmotion does not support HISMC which is crucial for performance, and because it does not support it, the same thing which you'll be able to view in UE in Twinmotion will bring your PC to its knees causing not responding states, out of memory cases or even crashes.