Missing Viewports in AutoCAD

Somehow, some genius created polygonal viewports and then deleted (?) the polyline. Whatever they did, now the viewport is unselectable for any editing or deleting. When recreation of an entire layout is not an option:

1. Type command: vpclip
2. Paste this into the selection: (SETQ A (ssname(SSGET "X" '((0 . "VIEWPORT")))0))
3. Draw a new viewport polygon.

You should now have an editable viewport with no change to the original viewport layout.

Thanks to cadhelp over at the autodesk forums.