Ahhh. Version updating seems to be a red herring. The real bulk imported list had blank circulation types and I generated these later in circulation types, but each item still had a blank unless edited individually only then did it assumed the first one by default. This caused the unfriendly blank page, an error message would have been nicer.
So how to edit or remove a circulation type name? The only option appears to be changing the duration. I now have a set of unusable types as I misapprehended their use.