DaemonUmbra

How are you sure that the server isn't open? Unless you added "pause" to your launch script which would show "Press any key to continue . . ." when the server stops the cmd window ought to just close when the server stops.

I'll need to see the end of the log, from what you gave me it looks to me like the server is starting normally.

So what is happening with the server, is it crashing or is it just slowing to a crawl? For future reference GitHub's Gist service will accept larger files than pastebin, though I am not sure of the maximum. And cutting off the end of a log is not usually helpful, even though it may seem helpful to cut off spam and make the file smaller it's not always obvious what is safe to cut out and what could actually be helpful in diagnosing a problem.

Mods are only designed to work on specific versions of Minecraft (and sometimes specific versions of Forge itself), you have to match them up correctly.

What mods do you have in your mods folder and did you have those mods in the mods folder when launching both versions?

Instead of just "java" in your .bat file you'll need to specify the full path to the Java 8 exe

You need to use Java 8

Thread Locked

Please don't even say MCreator, I have seen so many broken mods that were built with it that cannot be fixed because MCreator does not have the capability of allowing a "developer" to fix the bug correctly and the "developer" doesn't know Java so they can't make the mod properly in Java.

Please post your debug.log and please for the sake of the forum software use Pastebin or GitHub Gists, they are both linked in my signature.

Thread Locked

From what I'm seeing it looks like, you're trying to make a dedicated Minecraft drive on your computer. For this I must ask why? To my knowledge no matter what if you are using the default launcher you will want to point Forge's installer at your .minecraft folder, as that is where the launcher profiles are stored.

Please post your debug.log as described in my Signature.

You have not provided an override for an abstract method, according to the exception.

Try following these instructions:

Are you trying to make a portable Minecraft installation on a flash drive or something?

You'll want to use the jar version of the installer, not the exe. When specifying jar files, you'll want to include the .jar on the end. I have no idea why you put the universal's name on the end.

How are you downloading the modpack? If you are using a pack from CurseForge using the Twitch launcher it handles Forge differently and installs it for you. Note: A Forge "Installation" is not like your typical Windows program installation, it is paired with an instance or profile of Minecraft and is dependent on its location relative to said instance or profile..

It took me a single google search to find that Computercraft is now opensource on GitHub and has a 1.12.2 alpha build on CurseForge...

Try putting -Djava.net.preferIPv4Stack=true before your -jar argument

Thread moved to Modder Support

Adding the argument wasn't to fix your client, it was to get more info in the log about what's going wrong.

You can identify an MCreator mod by unzipping it (a .jar is essentially a .zip with some extra specifics) if you see a folder called "mod" with a folder called "mcreator" inside it then either it's an MCreator mod or someone's being a doof.

Click the 3 lines in the top right of the launcher Go to launch options Click the switch to enable advanced settings (switch should turn green) Click on the profile you're using Click the switch next to JVM Arguments to enable the text box Then scroll to the end of the text box and put in -Dfml.debugAccessTransformer=true (I have recently learned that some JVM args that I thought were good to go anywhere turned out position sensitive, so if this should go somewhere other than the end please correct me, Lex)

Another improperly coded mod, with the same issue on a different class... client-only stuff doesn't exist on the server but a mod is trying to access client-only stuff when it's on the server. Sadly I can't tell you which because it's happening before the mod has even finished being constructed, meaning the dev likely has no concept of sides.