I can't link my Nintendo Account. Support Code 804-3905 is displayed.

The Nintendo Account you're trying to link has already been linked to Super Mario Run user data. A single Nintendo Account cannot be linked to multiple sets of Super Mario Run user data.

■ If you'd like to link to a Nintendo Account with your current user data:

Try a Nintendo Account that has not yet been linked to Super Mario Run user data.

■ If you'd like to transfer user data to a Nintendo Account that's already linked with other user data:

Please follow the steps below:

1. Uninstall Super Mario Run.
   Note: Save data will be deleted while uninstalling.
2. Perform a new install of Super Mario Run.
3. Launch Super Mario Run.
4. Proceed to the Link a Nintendo Account screen and tap Link.
5. This will bring you to your Nintendo Account's linking screen. Sign in to the Nintendo Account you would like to link, and then tap Use this account.
6. If you agree to the User Agreement and Privacy Policy, tap Agree.