This can happen when a patron account has an old penalty that pre-dates current settings in Global Penalty Thresholds.

You can simply delete the message and the patron’s record will be cleared.

In patron account, select Messages> then highlight/select the relevant message>Select Actions for These Penalties/Messages>Remove Penalty Message.

For more detailed information on managing Patron Messages see http://docs.libraries.coop/sitka/_patron_alerts_notes_messages_and_notifications.html#_patron_messages