Save warning can't be actioned because no clue is supplied about with the problem actually is about id HOT 1 OPEN

The problem may be related to an "operator" / "operator:wikidata" mismatch - removing the latter did resolve the error.

I've no idea whether Craft Union (which is a pub company under the Stonegate umbrella) has its own wikidata entry or not, but whether a pub is a "Craft Union" pub rather than another Stonegate offering will give users a steer as to what to expect there (like many pub companies, Stonegate target different groups of sites at different markets. Sometimes (as here) these are distinguished by a separate operator name, sometimes not.

from id.