QuickBooks Error 15270 is an error that occurs when users try to download payroll updates in QuickBooks. The error is caused by several factors, such as a damaged QuickBooks installation, incomplete updates, or incorrect installation of updates. To resolve the error, users can try repairing QuickBooks installation, updating QuickBooks to the latest version, or resetting the update settings. Users can also try restarting their computer and the QuickBooks database server manager to fix the issue.