If you are experiencing issues when opening Spine, there are a few steps you can try to resolve the problem. First, check if there is any information in the spine.log file, which can provide insights into what might be causing the issue. The log file is located in the user home folder under Spine for Windows, /Library/Application Support/Spine for Mac, and ~/.spine for Linux. Additionally, you can try resetting Spine to its default settings by following the instructions provided here. If the problem persists, ensure that your Spine version is up to date, as updates often include bug fixes and improvements.

Update to the latest launcher. You can still run 3.8 with it, but it has many fixes like this issue.