lvcq Spinebot's answer is correct. There was a bug where a white attachment was showing for a single frame in spine-unity 3.8 when the active number of submeshes changes. This was fixed in later versions. Do you see SkeletonSubmeshGraphic components at each child of SkeletonGraphic, or a RawImage? Which exact version of the spine-unity runtime (name of the unitypackage, also listed in Assets/Spine/version.txt) are you using?
