I cannot make a hole

I can not make a hole on wall.
Please look at two pictures.
I pushed a surface to the opposite side,only to make two squares.
What should I do?

You need to add the model for us to really be able to see what the problem is.

Are the walls grouped in any way?

I can not understand very match.
ベレスの部屋.skp (6.6 MB)

You need to ‘Edit’ the group so the door is in the correct context.

In group


thank you.
I wad able to make a hole by separating a group.