IRD undertook a significant upgrade on the weekend of October 17-18. Part of this upgrade required that all companies re-consent for their payroll software to file on their behalf.
You company will have been disconnected from IRD. To reconnect and provide consent, go to Manage > Integrations and press the green Connect button against Inland Revenue:
If you have run any pays since Friday October 16 without having reconnected, you will need to resubmit these to IRD. For any of your pays marked as 'Withheld' or 'Error' , click into the affected pay cycle from the Tax screen and click the button on the right to find the Resubmit to the IRD option.