DaemonUmbra

You have a misbehaving coremod. Can't tell much else without a full log and it would be tricky even with one

Are you running optifine?

Try it without Optifine.

Please read the Logs section of my signature and post the applicable log in the appropriate manner.

The vanilla jar needs to be named minecraft_server.[version].jar (i.e. minecraft_server.1.12.2.jar) or Forge won't detect it properly

What’s the name of the vanilla server jar?

Looks like a broken coremod to me

You don't need MCP for mod development anymore. Edit: As you've already been told, looking at the sidebar

Please read the Logs section of my signature below and post the log that is most appropriate.

Locked and merged with your other identical thread.

Assuming you're downloading from this page: https://java.com/en/download/manual.jsp, only one of them is 64-bit and it's not the online one.

You need 64 bit Java, you are running 32 bit

Why are you trying to invoke the bat every time you type a command? Just open CMD and type java -version

In the command prompt

Run java -version for me please.

When I said open cmd or powershell in the same folder as the bat file I meant use the method of right clicking anywhere in the server folder that won't select anything and clicking "Open Command/Powershell window here". Pause needs to be on a new line, that's why it's not stopping the window from closing.

Ok let's try this: Open cmd or Powershell in the same folder as your start.bat (in this case it won't matter). Run this command: [your bat file] > ServerOutput.txt Send me the ServerOutput.txt that gets generated.

Again, do you mean the text editor you are editing your .bat file in closes instantly or do you mean the server instantly closes after you've changed 1024 to 4096?

Do you mean the file is closing when you try to change it or the server instantly closes when you've made the change?

I'm always suspicious when people say no logs were generated, logging is one of the first things that gets set up. If you haven't done so already, add pause to a new line at the end of your .bat, this will keep the window from closing immediately when the server stops, allowing you to see error messages that may have printed to the console.

What do you mean by "can't"? Please provide your debug.log, it has more information than latest.log

Ok, so close the launcher (Make sure it's properly closed, not hiding in the system tray), then go Documents\Curse\Minecraft\Install\Versions and delete the 1.12.2 folder. Restart Twitch and try launching the pack again.

You may have a corrupt minecraft jar, what launcher are you using?

You aren't giving the game enough RAM.

1.5.2 is not supported on these forums due to its age. Please update to a modern version of Minecraft to receive support.