I'm unsure if this is a bug, or me doing something wrong

The problem is, I am missing the possibility to animate, when importing my own data from Gimp, via Json.
I am unable to set keyframes in my own projects, but able to do so in the examples that come with Spine (and the default skeleton).
You can see the problem attached images.

In image problems I have higlighted my own skeleton. The possibility to animate won't appear.
In image problems2 I have highlighted a standard skeleton. The possibility to animate activates.

You can also see that the green key is present at the default skeleton, but not at the importet one.

Thanks in advance.