xiaoxiao According to the log, it appears that an error occurred in the startup of Spine itself. Perhaps you should encounter the same error if you simply try to run Spine from the command prompt without using the bat script.
I would suggest that you check the spine.log file to see why Spine 3.8.99 cannot be started. See the Troubleshooting page for information on where the spine.log file is stored:
https://esotericsoftware.com/spine-troubleshooting
By the way, the version of the Spine launcher you are using (4.2.02) is a bit out of date, so I would suggest upgrading your launcher version to tha latest version (4.2.19). This in itself may not be directly related to that error, but a newer version of the launcher may have improved log messages and may make it easier to identify what the problem is.
To upgrade your launcher version, download the latest installer from your licensing page and reinstall Spine.
