I've been plagued by an annoying issue since upgrading my Surface Pro 3 to Windows 10. One single app couldn't update, the Windows Scan app.
The error message, 0x803f8001, didn't give much in the way of directional information – which is the case with most Windows error messages. As has been the case with most app problems in Windows 10, the fix is to locate the app in the Windows 10 All Apps area and uninstall it (right-click and choose uninstall). After it uninstalls (give it a couple minutes to ensure it has been completely removed) jump back into the Windows Store, locate the app, and reinstall it.