DaemonUmbra

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)

Remove Optifine and OptiForge

Update Forge, this should be fixed

Debatable. There is a reason we recommend removing Optifine as an initial troubleshooting step.

Can you be more specific? What "current version of Forge" are you talking about?

It sounds like you generated the configurations but didn't use them, you should be launching the game from the IDE rather than Gradle

I remember seeing this error when someone forgot to re-gen their IDE runs after changing the Forge version. The args passed to modlauncher don't match the Forge it's trying to load.

Note step 5 in "From Zero to Modding"

Learn Java all the way before trying to mod, your issue here is not with Forge or Minecraft, but with not knowing how to use a method.

That is not the full debug.log, other than that I'm not exactly sure how we would go about deducing where the problem is (if there is one)

Or you could have used the "nogui" program argument, but yeah this seems to be an error in detecting whether the server is headless or not

All it means is the ad failed to load for one reason or another. And I can clearly see the download buttons right below the ad space that you seem to have tunnel-vision with

Don't use ! anywhere, it's a special character in Java path resolution

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

I'm saying run a dedicated server on your PC and see if it generates crashes properly

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

There's no crash here, but the symptoms sound like a mod reaching across logical sides, which is not a problem that can be fixed on the user end. Try running a dedicated server with the mod locally and see if you get a proper crash then.

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

Toss it out and use one of McJty's Tutorials. Technovision is known to encourage people to do exactly as he does without explaining how or why it works, leading to people getting confused when they miss something. (Yes, you are in this category)

Biomes O Plenty is broken, remove it

The name(s) of one or more of your mods indicate you did not get them from a reputable source. Please visit StopModReposts to learn why this is a bad thing.

Are you following a tutorial?

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

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