1. create a model (example the 20x20x20 cube) and save it.
2. The * behind the name is still visible. This should ONLY be visible if there are unsaved changes.
3. Select "New project"
4. Popup "Confirm where to save the current project".

OR

1. Open an existing chitubox file
2. Select "New project"
3. Popup "Confirm where to save the current project".

Tested on Windows 10 and OsX 12.5