Description

Creating a LAN world when owolib is installed prevents players without the library from joining, even though owolib (in my case) was only used for a client-only mod.
The mod I first noticed the issue with was PocketWatch, however I figured this was likely not an issue with PocketWatch, but rather with the library.
And indeed, even with owolib installed in isolation, it prevents players without it from joining.

Reproduction steps

1. Install owo-lib-0.8.5+1.19 and quilted-fabric-api-4.0.0-beta.19+0.64.0-1.19.2 on a Quilt Loader 0.17.6 client
2. Create a world and share it to LAN with this owolib client
3. Launch another client, either vanilla or another modded on without owolib, and try to join the LAN world
   ❌ -> You will receive an error message

The following errors will be produced respectively:

• Trying to join with another quilt client with no owo-lib results in:

   Missing entries for registry "minecraft:sound_event":
   -  owo:ui.owo.interaction
  

• Trying to join with a vanilla client results in: *Unsupported (vanilla?) client.

Hope I could provide all necessary information to help you debug the issue.

Solution

Detect if a LAN world is running and not a normal server, and don't enable owolibs server features, but run it as if it was client only on the hosting client.

Fixed in 0.9.0+1.19