nfcl The width and height of the skeleton are determined using the size of the attachments visible in the setup pose. In other words, if nothing is visible in the setup pose, the width and height of the skeleton will be zero.
I believe there are several possible workarounds for your issue. For example, you could display the attachments in the setup pose and have the animation start with the attachment hidden, or add a bounding box attachment to the skeleton and reference its size instead of width and height, or place several point attachments to reference their coordinates.
