Error 160-0103 is the combined result of user error and poor software design. Occasionally, while attempting to write over existing save data, the data will become corrupted causing an error whenever one attempts to boot the software.
This error has existed from day one, but has been more prevalent among users of Super Smash Bros. for Wii U. I encountered this error this morning, and have discovered an easy solution. This solution works if the error was caused by Super Smash Bros. for Wii U. I can't guarantee that it will fix other games affected by Error 160-0103, but it might. It will depend on whether the game utilizes shared save data.
Immediately after receiving the error, restart the console and create a new user from the user menu. Do NOT format your console, or it will brick and you'll have to ship it off to Nintendo for repairs. Once signed in as the new user, boot Super Smash Bros to the main menu just past the title screen. Then cancel back to the title screen, and close the software.
Sign out, and sign back in to your original account. From your original account, start Settings > Data Management. Navigate to wherever your data for Super Smash Bros. is stored. You should see at least three options: Shared Data, data associated with your primary account, and data associated with the new account. Delete the data associated with your primary account. Navigate back to the menu and start Super Smash Bros. for Wii U: it should now work with all saved data intact! Feel free to delete the new account now, or keep it around in case you ever face this error again.
Finally, ALWAYS make sure to navigate back to the title screen before closing Super Smash Bros. for Wii U.
