FRM-41312: Must have at least one writable item in block.
Cause: A block with the Insert Allowed Property or Update Allowed Property set to True must have at least one writable item. You attempted to make the only remaining base table item in the block not writable by setting either the Derived Column Property or Query Only Property to True.
Action: Set Insert Allowed or Update Allowed to False for the block, rather than setting Derived Column or Query Allowed to False for each item.
Trigger: ON-ERROR