Obviously, your plugin is misplaced. You need to put the plugin in the project root directory. like this:
After the addition is complete, if your engine version and the plug-in binary version are inconsistent. You also need to regenerate the VS solution and open the Sln file to recompile the Spine plugin.
After opening VS, make sure you can see the following directories
Then compile
Upon completion, your Spine plugin will work normally.
