Hi Jon,
we have got the root cause of the issue. there was schema change due to which , zfloor_location which was referring to floor_location got deleted.
from usp_contact table as well as wsp.mods.
we ware able to get the column back but it is not letting us change Field Type and SREL Table to foor_location its all grayed out for me.
Attaching the screen shot and highlighted are not editable for me: