Troubleshooting Error Code 0x800f081f: Missing Source Files on Windows Server 2016

To sort out the error code 0x800f081f in Windows Server 2016, try these methods:

1. Using the DISM tool: Open Command Prompt with admin rights and enter: DISM /Online /Cleanup-Image /RestoreHealth. This will check for and mend corrupted system files.
2. Running the Windows Update Troubleshooter: Head to Settings > Update & Security > Troubleshoot > Windows Update, and run the troubleshooter.
3. Manually installing missing files: If the error mentions a specific missing file, download it from Microsoft's website and install it manually.
4. Checking Group Policy settings: Make sure Group Policy settings aren't blocking updates. Go to Local Group Policy Editor > Computer Configuration > Administrative Templates > System > Specify settings for optional component installation and component repair, and ensure it's set to Enabled.
5. Verifying the Windows Update service: Make sure the Windows Update service is up and running. Go to Services and ensure the Windows Update service is set to Automatic and is running.
6. Performing a system restore: If none of the above fixes work, try restoring the system to a previous point before the error popped up.