As with the previous report, what we'd really need in order to investigate is the problem scene. Also, please let us know more about what you mean by "once it is converted to Corona" - are you installing Corona, loading a non-Corona scene, running the Corona converter, saving the scene, then re-opening it and the problem happens then? Or do you mean some other set of steps.
For uploading scenes privately, see
https://corona-renderer.com/upload (in case it's a scene that can't be shared publicly here on the forums). Thanks!