How to solve the error code 0x800f081f: The source files could not be found in Windows Server 2016

There are several ways to solve the error code 0x800f081f in Windows Server 2016:

1. Use the DISM tool: Open Command Prompt as an administrator and type the following command: DISM /Online /Cleanup-Image /RestoreHealth. This will scan and repair any corrupted system files.
2. Use the Windows Update Troubleshooter: Go to Settings > Update & Security > Troubleshoot > Windows Update and run the troubleshooter.
3. Install the missing files manually: If the error message specifies a missing file, download it from Microsoft's website and install it manually.
4. Check the Group Policy settings: Make sure that the Group Policy settings are not blocking the installation of updates. Go to Local Group Policy Editor > Computer Configuration > Administrative Templates > System > Specify settings for optional component installation and component repair and make sure it is set to Enabled.
5. Check the Windows Update service: Make sure that the Windows Update service is running. Go to Services and make sure that the Windows Update service is set to Automatic and is running.
6. Perform a system restore: If none of the above solutions work, try performing a system restore to a previous point in time when the error was not present.