LAN multiplayer is not working in a game

[lucas-xk]

Describe the bug
In the game "Cardfight!! Vanguard Dear Days 2", the LAN multiplayer is not working.

The game was released in January 29, 2025.

I host the lobby using one instance of the game on a computer — let’s call it Machine A. From another computer, Machine B, I can see the lobby just fine, but when I try to join it, it stays stuck on "connecting" forever.

Strangely, on Machine A, it looks like the player from Machine B has successfully connected — their name appears in the lobby. But on Machine B, it's still endlessly loading as if the connection never completes.

Emulator version
release-2025_04_20

Debug log
Machine A - Log of the game that creates the lobby.log
Machine B - Log of the game that tries to connect to the lobby.log

I recommend downloading these files instead of trying to see them in Google Drive.

steam_settings file
steam_settings from Machine A
steam_settings from Machine B

Requirement

• I am uploaded debug log.
• I am uploaded steam_setting file.
• I am sure the game not using 3rd party server (Photon, Playfab, GC, etc).
• I am sure can run the game offline.

To Reproduce
Steps to reproduce the behavior:

1. In Machine A, create a multiplayer lobby.
2. In Machine B, try to connect to the lobby from Machine A.
3. The game from Machine B will load forever.

Expected behavior
Game from Machine B should successful connect to the lobby of Machine A.

Screenshots
In Machine A, I create the lobby choosing "Make a Room"
In Machine B, I choose "Enter a Room"

The room created by Machine A is in the Machine B list:

After clicking in it, Machine B will stuck in this screen:

In machine A, I can see both members. One is from Machine A (itself) and the other is Machine B (which is stuck at "connecting" screen):

Additional context
I already tried using the regular steam_api64.dll instead of the experimental one, but the result is the same.
I'm using different steam user IDs for both computers/games.

[universal963]

I am not sure if this is the cause of the problem but I have indeed found missing implementation. Please try #264 and see if it works.

[lucas-xk]

I am not sure if this is the cause of the problem but I have indeed found missing implementation. Please try #264 and see if it works.

Thanks for the response.

I'm trying to compile, but there aren't any files in third-party folder. How can I compile? I'm using Visual Studio.

[universal963]

You don't need to compile it yourself, this repo already has GitHub Actions set up so you can directly download artifacts here.

[lucas-xk]

I downloaded the file, and it works!! Thank you so much for that!

I would like to ask a question. In Dear Days 1 there is no lobby feature, only matchmaking. Using the Goldberg Emulator can I play multiplayer if it is with matchmaking?

[universal963]

In theory as long as the game doesn't need any third party servers to connect to each other, you can use it to play multiplayer.

[lucas-xk]

I see. Thank you very much once again.