wangzi

The red rectangles displaying the text "Required PRO" indicate that you have Spine Essential, which does not support meshes. You've likely loaded a skeleton containing meshes.

If you want to use meshes, you need to upgrade your Essential license to Professional. For beginners, the Essential version is sufficient to learn the basics of skeletal animation.
However, if you want to take advantage of advanced features like mesh deformation and physics, you'll need the PRO version.