[Wii Sports Club issue] Am I forced to create a Nintendo Network ID, and is there any risk ?

[WiiFanAix]

Hi all. I have a softmodded Wii U with Tiramisu and game dumps on a USB hard drive. Everything works.

I have an issue with Wii Sports Club though. On startup, the game displays an error saying that it needs a Nintendo Network ID.
The first time I used it, I just dismissed the error and could play locally without any issues.
But the second time I used it, I got another error saying the "additional data" was corrupted and needed to be erased.
So I erased that data (672 KB) and relaunched Wii Sports Club.
I got the NNID error and I dismissed it again.
But now I see that all sports are greyed out, so I can't play any of them locally anymore.

Hence my questions :
- Am I forced to create a NNID just to play Wii Sports Club locally ? So far I only have 3 local accounts, and I'd like to keep them that way, I don't need any online gaming features.
- Is there any risk in doing so with a softmodded Wii U ?

Thanks in advance.

 

[WiiFanAix]

Nevermind, I ended up solving it. It was a mix of two problems :
- My SD card not booting properly (the payload wasn't loaded on startup)
- Me deleting the supposedly "corrupted" additional data (DLC) caused Wii Sports Club not to start properly

First I had to eject/insert the SD card several times for it to work correctly.
Once the payload was properly loaded, installing the additional data again with WUP Installer did the trick.