Attempting to define shelf item with a key already associated with the shelf.

#6021   Run-time catchable error

Attempting to define shelf item with a key already associated with the shelf.

Additional Information

For X shelf 'Y'; For key 'Z'.
    where X is either counter, stream or switch.

Explanation

OmniMark is trying to assign the key Z to a shelf which already has item associated with the key.