Emulator

Game Name [ID]

New Super Mario Bros. Wii [SMNE01]

MD5 Hash

05022377c66dcc13dd8308b333c202db

What's the problem?

Checking the "Load Wii Save" option in the netplay room seems to prevent the netplay session from booting into the game. Clicking the "Start" button will simply send over your memory card files and AR/Gecko codes, then once done, just not do anything. No booting the game. It just acts like nothing happened. Disabling it lets the game work (and controllers to boot if you set them up correctly which we did), but doing so causes the game to save in game, but once the netplay session is over, whatever save file the second player, not the host, had before the session even began, ended up replacing the local game save on the host's machine!

Here's an example:
The host (P1) has a file up to World 5, P2 (the guy connecting) has a save file for World 1.
Once the netplay session starts, P2's save OVERWRITES THE HOST'S. Not the other way around like it is supposed to!

The specific events that occurred when we first discovered this was as follows:
After reaching World 5 via a cannon, my friend and I saved the game, and quit to title screen. The file said 20 lives at World 5. I closed the game, and after 5 minutes, reopened it to see the save rolled back to 5 lives at World 1, thus undoing all the work we did over that past hour.

The only workaround I could see coming from this would maybe check and see if giving the host's save file to everyone else may fix the issue, but syncing Wii saves automatically apparently just doesn't work even though it does for GameCube games.

What steps will reproduce the problem?

1. Boot the game with provided save file by yourself (no netplay). Verify the save (see details below).
2. Set controller configs for each player in netplay group using emulated Wii Remotes (each person must share controller configs with each other and Player 1's controls go into "Wii Remote 1" for everyone's input settings, as does Player 2's into "Wii Remote 2", and so on so forth. Make sure background input is on by default!
3. Have everyone connect to netplay session using port forward.
4. Boot the game, examine your save files again (see if they match. Hint: they won't.) Congrats! You found the bug! If that doesn't result in anything, use the cannon in the save provided, then save, quit the netplay session, and check again.

Is the issue present in the latest development version? For future reference, please also write down the version number of the latest development version.

5.0-16120

Is the issue present in the latest stable version?

Yes, 5.0-16120

What are your PC specifications? (CPU, GPU, Operating System, more)

My PC: R9 5950X, RTX 3080, 64GB RAM
Friend's PC: i5 10300H, GTX 1650MQ, 8GB RAM
Both on Windows 10 using OpenGL
This issue is not related to graphics as we we're running full speed the whole time with no graphical errors.