Set/Transfer Skeleton

Clicking this button sets the skeleton and skin weights of an interchangeable base character in the right scene to the default, or transfers them from the interchangeable base character in the middle scene.

If the skeleton of the interchangeable base character in the middle scene is not a supported skeleton, the following warning dialog is pop up:

then you need to check all the primary bones in the bone tree as shown in the following figure:

then click the "Set/Transfer Skeleton" again.