Hi zbvg.kta84_742487, Thanks for your feedback! Currently, we can't reproduce this issue. When this issue happen next time, please save your project as iProject via Content Manager, and send this project to us. You can upload this project to cloud service such as Google drive and attach the download link in your next comment. You can also set the comment as private. Thanks for your help! Calvin Reallusion
I also give you a possible solution in that thread, i.e. that no initial keyframe was present.