: Visit your personal Spine license page , which was emailed to you upon purchase. Download and install the latest Spine launcher for your operating system.
: If 3.8.99 is not in the quick-list, select Other... and manually type 3.8.99 to trigger the download. Spine 3.8.99 Download
: Open the launcher. Before the editor starts, click the version number (or "Latest stable") to open the version selection menu. : Visit your personal Spine license page ,
While newer versions introduce advanced features like the Graph Editor, version 3.8.99 is prized for its stability and specific feature set: Versioning - Spine User Guide Spine 3.8.99 Download