I'm trying to make a mod in minecraft (1.12.x) in eclipse, but i'm having a lot of problems with it. Many I managed to solve them but this problem not:

Plugin with id 'net.minecraftforge.gradle.forge' not found.

This problem is caused by this command below

Quote

gradle setupDecomWorkspace eclipse

This is my build.gradle file

buildscript {
    repositories {
        maven { url = 'https://maven.minecraftforge.net/' }
        mavenCentral()
    }
    dependencies {
        classpath 'net.minecraftforge.gradle:ForgeGradle:5.+'
    }
}
        
apply plugin: 'net.minecraftforge.gradle.forge'
// Only edit below this line, the above code adds and enables the necessary things for Forge to be setup.
apply plugin: 'eclipse'
apply plugin: 'maven-publish'

version = '1.0'
group = 'com.yourname.modid' // http://maven.apache.org/guides/mini/guide-naming-conventions.html
archivesBaseName = 'modid'

sourceCompatibility = targetCompatibility = compileJava.sourceCompatibility = compileJava.targetCompatibility = '1.8' // Need this here so eclipse task generates correctly.

minecraft {
    // The mappings can be changed at any time, and must be in the following format.
    // snapshot_YYYYMMDD   Snapshot are built nightly.
    // stable_#            Stables are built at the discretion of the MCP team.
    // Use non-default mappings at your own risk. they may not always work.
    // Simply re-run your setup task after changing the mappings to update your workspace.
    //mappings channel: 'snapshot', version: '20171003-1.12'
    mappings channel: 'snapshot', version: '20171003-1.12'
    // makeObfSourceJar = false // an Srg named sources jar is made by default. uncomment this to disable.
    
    // accessTransformer = file('src/main/resources/META-INF/accesstransformer.cfg')

    // Default run configurations.
    // These can be tweaked, removed, or duplicated as needed.
    runs {
        client {
            workingDirectory project.file('run')

            // Recommended logging data for a userdev environment
            property 'forge.logging.markers', 'SCAN,REGISTRIES,REGISTRYDUMP'

            // Recommended logging level for the console
            property 'forge.logging.console.level', 'debug'
        }

        server {

            // Recommended logging data for a userdev environment
            property 'forge.logging.markers', 'SCAN,REGISTRIES,REGISTRYDUMP'

            // Recommended logging level for the console
            property 'forge.logging.console.level', 'debug'
        }
    }
}

dependencies {
    // Specify the version of Minecraft to use, If this is any group other then 'net.minecraft' it is assumed
    // that the dep is a ForgeGradle 'patcher' dependency. And it's patches will be applied.
    // The userdev artifact is a special name and will get all sorts of transformations applied to it.
    minecraft 'net.minecraftforge:forge:1.12.2-14.23.5.2859'

    // You may put jars on which you depend on in ./libs or you may define them like so..
    // compile "some.group:artifact:version:classifier"
    // compile "some.group:artifact:version"

    // Real examples
    // compile 'com.mod-buildcraft:buildcraft:6.0.8:dev'  // adds buildcraft to the dev env
    // compile 'com.googlecode.efficient-java-matrix-library:ejml:0.24' // adds ejml to the dev env

    // The 'provided' configuration is for optional dependencies that exist at compile-time but might not at runtime.
    // provided 'com.mod-buildcraft:buildcraft:6.0.8:dev'

    // These dependencies get remapped to your current MCP mappings
    // deobf 'com.mod-buildcraft:buildcraft:6.0.8:dev'

    // For more info...
    // http://www.gradle.org/docs/current/userguide/artifact_dependencies_tutorial.html
    // http://www.gradle.org/docs/current/userguide/dependency_management.html

}

// Example for how to get properties into the manifest for reading by the runtime..
jar {
    manifest {
        attributes([
            "Specification-Title": "examplemod",
            "Specification-Vendor": "examplemodsareus",
            "Specification-Version": "1", // We are version 1 of ourselves
            "Implementation-Title": project.name,
            "Implementation-Version": "${version}",
            "Implementation-Vendor" :"examplemodsareus",
            "Implementation-Timestamp": new Date().format("yyyy-MM-dd'T'HH:mm:ssZ")
        ])
    }
}

// Example configuration to allow publishing using the maven-publish task
// This is the preferred method to reobfuscate your jar file
jar.finalizedBy('reobfJar') 
// However if you are in a multi-project build, dev time needs unobfed jar files, so you can delay the obfuscation until publishing by doing
//publish.dependsOn('reobfJar')

publishing {
    publications {
        mavenJava(MavenPublication) {
            artifact jar
        }
    }
    repositories {
        maven {
            url "file:///${project.projectDir}/mcmodsrepo"
        }
    }
}

I changed the build.gradle file:

classpath 'net.minecraftforge.gradle:ForgeGradle:3.+' -> I changed it to -> classpath 'net.minecraftforge.gradle:ForgeGradle:5.+'

apply plugin: 'net.minecraftforge.gradle' -> I changed it to -> apply plugin: 'net.minecraftforge.gradle.forge'

 

Anyone can help me?

The version you are using is no longer supported on this forum.

Please update to a modern version of Minecraft to receive support.

Currently supported versions are 1.19.2 (Latest) and 1.18.2 (LTS).