A cause of error 0x80070241 when upgrading a Windows 10 to Windows 10 build is that you may have the latest Windows ADK Insider Preview (build 14965) installed. The solution is to uninstall the Windows ADK Insider Preview and then perform the upgrade. The issue is caused by some interference with the DISM tool, and the setuperr.log points to problems mounting the WinRE.wim file. This occurred trying to upgrade from Windows 10 build 14971 with Windows ADK 14965 to Windows 10 build 14986.