Floor maps link error

[lwrubel]

Error below for the item viewable in WRLC Catalog at
https://catalog.wrlc.org/cgi-bin/Pwebrecon.cgi?BBID=2268753

unable to render bibid: 2268753
Traceback (most recent call last):
  File "/launchpad/current/launchpad/lp/ui/views.py", line 74, in item
    holdings = add_floormap_link(holdings)
  File "/launchpad/current/launchpad/lp/ui/views.py", line 133, in add_floormap_link
    item['DISPLAY_CALL_NO'].replace(' ', ''))
AttributeError: 'NoneType' object has no attribute 'replace'

Request repr(): unavailable