Please find my reply in this topic: viewtopic.php?p=30841#p30841electric wrote: ↑12 Jul 2021, 10:23 I had the same issue with empty step file as described above, while 3D model was loading correctly in Diptrace. Now I updated to 4.1.3.1 release and the model gets into infinite loop while loading in Diptrace. It seems to choke on some component and starts over again, repeating forever. I have to end task the program to stop it.