I've been having so many issues with the level editor that I can't make my level.

1. I can't delete objects
2. When I load a map some of my objects disappear.
3. When I move a ground piece with a hole, the actual hole is still in the previous spot.
4. When I want to move a flagpole into a hole, the yellow box will either be above the hole or too far below the hole.
5. I can't copy objects by holding shift like I used to

Is there a way to fix this because I can't work on my level without being able to even delete objects.