Hi Xiu,
let's assume you have done some modifications in Application::Application and you have deleted Effects::PointEffect accidentally.
When you now save the project via Ctrl+S you get:
When you close the project, again a message appears and informs you about the modified Mosaic:
Everything fine. Now, when you reopen your project, the unit Application contains the latest version and the Mosaic unit Core is unmodified.
Can you confirm that? If not, what version are you using?
Best regards,
Manfred.