This mod is a small patch to let your Modded Minecraft 1.12.2 (with Forge) and 1.13 (with Optifine or not) support Java 10.
As we know in Java 9 and 10 Oracle released Project Jigsaw which causes Forge broken because Forge used very many 'unsupported' and 'internal' API in Java. Also, many internal implements of Java are changed and thus Mojang LaunchWrapper failed to run.
This mod is a part of a large magic mod project Alchemy (work in progress) by NekoCaffeine, from AmadeusSystems.
This patch is NOT a forge mod! DO NOT add it to your mods folder!!!
Instead, this patch is a Java Agent, which used to modify class before they're loaded. LaunchWrapper fails before the mods folder are read, so we can only use this form of patch.
Download the patch .jar file, place it into your .minecraft folder and add a Java(JVM) argument (not "Minecraft/Game argument!")to your Minecraft Launcher, like this:
-javaagent:jar file name
for example if the name of the patch file is "Alchemy-Agent-1.0.0-pre.jar", your argument added should be:
If you don't how to add JVM argument please Google it. for example