Hi Tim!
I just saw a pull request for a more specific error message, so we're working on this. Meanwhile...
In the current version only one instance of the plugin works at a time. So you can't have two VSCode workspaces open, with one targeting InDesign and the other targeting Photoshop.
Have you tried following the following troubleshooting steps?
- Make sure the ExtendScript ToolKit stand-alone application is closed
- Close the target application (or in your case all the target applications)
- Close Visual Studio Code
- Make sure there are no VS "Code Helper" processes in the Activity Monitor (Mac) or Task Manager (Windows)
- Restart Visual Studio Code
- Does it work then?
- If not, does a reboot help?
Let us know!