Hi Paul!
Sorry to hear you've run into this setback! Glad to see Joe has been helping you!
As Joe shared, we typically see this error when files aren't being saved locally. Working off of a network or shared drive may cause erratic behavior. Also, the Articulate 360 desktop app should notify you when a new update is available. If you're not seeing the option to update, you can check for updates manually.
If you're still running into trouble, it would be helpful to see a copy of the .story file for testing on our end. Feel free to attach it here in the discussion or privately through a support case.
