Deleting Unsaved Sprite Save All

[ElliotRoe]

Summary

Deleted an unsaved sprite and tried to run and got the screenshot error

Steps to Reproduce

1. Create a new project with the "new" file menu option
2. Add, save, and run script move(10) to this sprite
3. Delete this sprite
4. Add another sprite
5. Add move(10) to this sprite
6. Run