Delete outline

I want to delete the following object (sorry, cannot upload screenshot because "An error occurred, please try again or contact your administrator."):

```

LISTING: 1 element(s)

     < SHAPE(auto-generated) >

       class         CAVITY

       subclass      BOTTOM

  Shape is solid filled  in Smooth mode

  Area:   6.350  (sq cm)

Exterior boundary: 

  segment:xy (-13200.00 12000.00) xy (12200.00 12000.00) width (0.00) 

  segment:xy (12200.00 12000.00) xy (12200.00 -13000.00) width (0.00) 

  segment:xy (12200.00 -13000.00) xy (-13200.00 -13000.00) width (0.00) 

  segment:xy (-13200.00 -13000.00) xy (-13200.00 12000.00) width (0.00) 

*** Part of the Dynamic Shape ***

       class         BOUNDARY

       subclass      BOTTOM

  Shape priority:        0

  Number of etch shapes: 1

  Dynamic fill style:    SMOOTH

  Area:   6.350  (sq cm)

Original boundary: 

  segment:xy (-13200.00 -13000.00) xy (12200.00 -13000.00) width (0.00) 

  segment:xy (12200.00 -13000.00) xy (12200.00 12000.00) width (0.00) 

  segment:xy (12200.00 12000.00) xy (-13200.00 12000.00) width (0.00) 

  segment:xy (-13200.00 12000.00) xy (-13200.00 -13000.00) width (0.00) 

```

When I select this object and click on "delete", the software says:

```
Selected item not valid for current operation, ignored: Shape(auto-generated) "Not On A Net, Cavity/Bottom"

No valid items selected for the current operation, exiting.

```

How can I delete this?