Invisible components

How do i solve invisible components problem. I was building a function and the screen suddenly went blank. If i click on the screen I can see the components in the left navigation menu and i can edit and work on it but i cannot see the components in the screen. I see the outlines but nothing more

For some freaky reason the components were sent to the back of the screen by the application. I simply sent the components to the front and problem fixed. Thank you. I don’t know how it happened but that is how they got sent to the back of screen but I fixed it