If schedule fails, it mark self as invalid - it is indicated in schedules list and also in menu. If schedule runs only once a week, it stays there and this behaviour causes user gets used to error and can miss real error later.
Allow reset state of schedule. There will be confirmation dialog for this action.
Action should be available in actions menu in table and in actions menu in detail toolbar. Action will be available only for failing schedules.
State of schedule is persisted in schedules table so it is possible to reset its state. Reseting state means its state is empty (not success).