DaemonUmbra

Are you using mods or making them?

The bit before the (MavenPublication) is simply the name of the publication. The bit inside the brackets is what gets published, GitHub is suggesting publishing everything built from Java, which may or may not be what you want, I recommend testing by publishing to mavenLocal or mcmodsrepo first. All in all GitHub Packages should just be a maven that requires authentication

No idea, I don't own a Mac. Try google.

That sounds like a connection issue, what exactly is the setup you have and is there a specific reason to not host a dedicated server locally?

Lex has said that he'll poke around with it when he gets his Mac Mini... however until he gets it and starts poking around there is literally nothing any of us can do because none of us own Macs and we're not all that motivated to go out and buy something expensive, therefor giving money to the same company that broke what you're asking us to fix.

Delete C:\Users\admin\AppData\Roaming\.minecraft\config\fml.toml and try again.

Does it mention anything about checking a console for the error?

Really old Minecraft versions are no longer supported on this forum. Please update to a modern version of Minecraft to receive support.

Uninstall every version of Java that you have and then reinstall whatever Java versions you need. Note: I don't mean reinstall them one by one I mean there needs to be a point where there is one version of Java left and it gets uninstalled so it will clear out shared stuff to be regenerated when you reinstall the new one.

Try Johann Löfflmann's JarFix utility.

This sounds like you're starting a vanilla server, how are you starting the server?

1.12 is no longer supported on this forum. Please update to a modern version of Minecraft to receive support.

Please provide debug.log (more info on where it is and how to provide it in my signature below, just expand the spoiler)

Use datagens

Are you still crashing? Are you still using 1.16.4 Optifine on Minecraft 1.16.3?

Then use whatever Forge version is compatible with the most recent version of Optifine, it's their restriction not ours Alternately you could uninstall Optifine and be free of that restriction.

You follow the solution that was already given...

So it's not that you don't understand the solution, its that you refuse to apply the solution because you don't believe Optifine is at fault

What about the solution confuses you?

Did you try the same solution?

1.12 is no longer supported on this forum. Please update to a modern version of Minecraft to receive support.

1.8 is no longer supported on this forum. Please update to a modern version of Minecraft to receive support.

1.8 is no longer supported on this forum. Please update to a modern version of Minecraft to receive support.

The installer log should be in the same place as the installer file, either with the same name as the installer with .log on the end or just called installer.log

In that case I guess try deleting /Users/[surname]/Library/Application Support/minecraft/libraries/net/minecraftforge/forge/1.16.4-35.1.4/ and running the installer again. If that doesn't work provide the installer log.