It looks like you tried to change the default value of a table.
Instead, try this:
- Double left click the table. (This will place a command, similar to SELECT * FROM peq.zone z; in the execute box.)
- Press the green 'Execute' button.
- Toggle the 'Edit' button on the bottom.
- Double left-click any field to edit.
- Press 'Apply Changes' when you are finished.
Check out the (contents of the) 'variables' and 'rule_values' tables, too. Best of luck.