To run from source or make a JAR you'd need to setup libgdx. You can just use the JARs here:
http://esotericsoftware.com/spine-skeleton-viewer
3.8.99 Skeleton Viewer should be able to load data from 3.8.75. If not, you can try exporting with 3.8.99 and see if 3.8.99 Skeleton Viewer can open that.
If you just need to review animations in the data, you could import it into the Spine editor to view it.
