The error you are encountering when trying to import the .skel file into Spine is likely due to a version mismatch between the exported .skel file and the version of Spine you are using. Here are the steps you can follow to resolve this issue:
Identify the Version: Open the .skel file in a text editor and look for the version number near the beginning of the file. It will look something like 3.5.51 or 3.8.81.
Downgrade Spine: Set your Spine editor to the version that matches the version number found in the .skel file. You can do this by going to the Spine settings and selecting the appropriate version. For example, if the version is 3.8.81, you need to run Spine with that version.
Import and Save: Import the .skel file in the downgraded version of Spine. Once imported, save the project as a .spine file.
Upgrade and Export: Open the saved .spine project file in the latest version of Spine or the version that matches your runtime. Then, export the project as a JSON or binary file that works with your runtime.
Here are some useful links for more detailed instructions:
If the .skel file contains meshes and you are using Spine Essential, you will need to upgrade to Spine Professional to view, edit, or export them correctly.
If you continue to experience issues, it might be due to the .skel file being exported without nonessential data, which can cause problems with meshes. In such cases, you may need to contact the original creator for the .spine project file or ensure that the source images do not have padding around them.
