When I transform, nothing happen.
thank you very much for your support request.
Try the following:
In case the arm's mesh also doesn't move with the bone, the bone you are trying to move has no vertices applied (i.e. it is not skinned). You need to fix this in a 3D modeling application.
In case the mesh moves with the bone now, please send the model to me (without textures if you want) so that I can further investigate as in that case it might be a UMotion bug. You can send it to me via the email support form.
Customer support service by UserEcho