Troubleshooting Solutions:
QuickBooks Desktop Error 15270 often occurs during payroll updates when a file is missing or the update process is interrupted. To resolve this issue, follow these steps:

Verify Payroll Subscription:

Ensure your payroll subscription is active. Go to "Employees" > "My Payroll Service" > "Account/Billing Information" to verify.
Update QuickBooks:

Make sure your QuickBooks is up-to-date. Go to "Help" > "Update QuickBooks Desktop" > "Update Now" tab and click "Get Updates." Restart QuickBooks and install the updates.
Run QuickBooks as Administrator:

Close QuickBooks. Right-click the QuickBooks icon on your desktop and select "Run as Administrator." Try the payroll update again.
Check Internet Connection:

Ensure you have a stable internet connection. A weak or unstable connection can interrupt the update process.
Adjust User Account Control (UAC) Settings:

Lower UAC settings temporarily. Go to "Control Panel" > "User Accounts" > "Change User Account Control settings" and move the slider to "Never notify." After updating, reset UAC to its original setting.
Install a Digital Signature Certificate:

Navigate to "C:\Program Files\Intuit\QuickBooks." Right-click the QBW32.exe file, select "Properties," and go to the "Digital Signatures" tab. Ensure Intuit is selected and click "Details" > "View Certificate" > "Install Certificate." Follow the prompts to install.
Download the Latest Payroll Tax Table:

Go to "Employees" > "Get Payroll Updates." Select the option to download the entire payroll update and click "Update."
Repair QuickBooks Installation:

Go to "Control Panel" > "Programs and Features," select QuickBooks, and choose "Repair." Follow the prompts to repair your installation.
By following these steps, you should be able to resolve QuickBooks Desktop Error 15270 and successfully update your payroll. If the issue persists, consider contacting QuickBooks support for further assistance.