The lookup that answers a write refused by protection, or null for any other failure.
Parameters
error: unknown
Returns string|null
Remarks
The refusal itself is written for a person at a dialog ("unprotect the sheet"); a script needs
to know what is still allowed and where. Tested by name, since the error routinely crosses a
bundle boundary on its way to the host that reports it.
The lookup that answers a write refused by protection, or
nullfor any other failure.