Field not found

[brightrim]

1 Oct 6 21:18:01 Script (err): World::isItemOnField: Field (781, 727, 2) was not found!

Opening a trapdoor, door or staircase with a key checks all surrounding tiles if you are not facing it.
If this is done at the edge of a property where no field exists, it can lead to this error.
No functional difference as it just ignores the empty fields, but fixing this does clean up back-end.