DaemonUmbra

1.8.9 is no longer supported on this forum due to its age. Please update to a modern version of Minecraft to receive support.

Cubex2 appears to be broken and trying to access client-only code on the server side.

My "Signature" is the thing below each of my posts(the thing that says "...please expand the spoiler below..."), I've tried to fill it with instructions on how to help us help you, unfortunately that makes it a bit long so I've used collapsing spoiler tags to keep it manageable. In this case the section that will help you is the "Logs" section.

Please read the "Logs" section of my signature and provide the appropriate log in the appropriate manner.

Mods for 1.12.X will not be compatible with 1.13.X Optifine does not have a Forge-compatible version yet.

Please read the logs section of my signature and provide the appropriate log in the appropriate manner.

1.7.10 is no longer supported on this forum due to its age. Please update to a modern version of Minecraft to receive support.

Please read the "Logs" section of my signature and provide the appropriate log in the appropriate manner.

For more info on posting logs please read the "Logs" section of my signature. What version of Minecraft are you using?

Well I just took another look at Multicraft and I don't know how I missed it... there's a "Memory" field in the server panel that acts as -Xmx and under advanced there's "Startup Memory" for -Xms. I'm afraid anything more is on your host. As far as I can see Multicraft's startup argument customization only goes as far as toggling pre-set arguments on or off and these arguments are set in a file you apparently don't have access to.

I should mention that when I talk about directories I'm talking about filesystem directories, not the page groups in Multicrafts panel, meaning you would have to set up FTP to access them, if you are allowed to access them at all. You cannot add command line arguments through anything inside Minecraft, there's simply nothing designed for that purpose and everything loads after it's already too late to add arguments.

Setting up Multicraft locally I found the conf files in the Multicraft config directory, which is separate from the server's own directory. Personally I would like to say that after this test I have vowed to never use Multicraft to actually run a server, I'd rather have plain old FTP and ssh rather than this and there are other hosts with proprietary panels that I prefer.

You will need to get Java from https://java.com/ (Oracle) or https://openjdk.java.net/ (OpenJDK), note that you will need to look around to make sure you get Java 8, 64-Bit for things to work properly.

1.7.10 is no longer supported on this forum due to its age. Please update to a modern version of Minecraft to receive support.

Please read the EAQ or my signature and provide the appropriate log.

Please stop bumping your thread.

You are running 1.12.2 with 1.8.9 Optifine, this is not going to work at all. Optifine versions are only tested to work with specific builds of Forge, as stated in their changelog, please make sure you get an Optifine and Forge version that match.

The lack of a debug.log is an issue that the team hasn't fixed yet, there are a couple known ways to do so and they're not sure which will be best in this case.

That's a 1.12.2 debug log, 1.13.2 doesn't have it.

Is this a question of how you allocate ram to Forge/Minecraft? Or is it a case of you're trying to add ram to it and it doesn't seem to be having any effect?

Please read the EAQ or my signature and provide your latest.log

I'm not getting that error, but searching online suggests a corrupted cache as a possible cause

Can I get the exact MDK version and your exact steps (i.e. what gradle commands you used and in what order)?

A couple things wrong here. I'm not 100% sure Forge is fully compatible with OpenJ9, I would recommend only using Oracle Java or OpenJDK. In your crash it is effectively saying that a mod is missing one of its own classes, suggesting the jar is corrupted or otherwise incomplete. Where are you getting your mods and are you sure they were fully downloaded before you moved them into the server? Please provide your debug.log, it has more info than the other logs (more info in my signature).

1.7.10 is no longer supported on this forum due to its age. Please update to a modern version of Minecraft to receive support.