When QuickBooks payroll not updating, it can cause significant payroll processing delays. To troubleshoot, first, ensure your QuickBooks software is updated to the latest version. Verify your payroll subscription is active by checking your account details. Clear any pending payroll updates and try downloading the updates again. If the problem persists, restart QuickBooks and your computer. Additionally, check your internet connection and firewall settings, ensuring they are not blocking QuickBooks. If none of these steps resolve the issue, consider repairing your QuickBooks installation or contacting QuickBooks support for further assistance. Keeping software and subscription details current helps avoid update issues.