Unable to delete a screen

Hello AB professionals,

I am using FactoryTalk View Studio v11. I am basing on an old project to build my application. I restored the project from a .mer file.

I deleted or renamed some old screens, saved and closed the project. But when I open the project next time the screens I deleted still show up. When I click on it it will show an error message "Component does not exist". 

In the FactoryTalk ME application, I right click a screen name on the left tree under the Graphics, and then click "Delete" or "Remove", the display would disappear at that time. But it persists on coming back next time I open the project.

If you know the solution to resolve please reply. It is much appreciated.

Thank you.

Lei