IntelliJ Community edition: 2020.3.3

When I create a new project, the project is unable to build and is covered in red errors saying various symbols cannot be resolved. When I go to project structure There is a problem that comes up which says

Things I have tried:
Invalidate caches / restart
Uninstall/reinstall plugin
Uninstall/reinstall IntelliJ
Uninstall/reinstall JDK
Used the following JDKs:

Build Gradle:

buildscript {
    repositories {
        maven { url = 'https://files.minecraftforge.net/maven' }
        jcenter()
        mavenCentral()
    }
    dependencies {
        classpath group: 'net.minecraftforge.gradle', name: 'ForgeGradle', version: '3.+', changing: true
    }
}

apply plugin: 'net.minecraftforge.gradle'

group = 'PanelsFA'
version = '1.0'
archivesBaseName = 'PanelsForAll'

sourceCompatibility = targetCompatibility = compileJava.sourceCompatibility = compileJava.targetCompatibility = '1.8'

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: 'stable', version: '39-1.12'
    // 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'

            mods {
                panelsforall {
                    source sourceSets.main
                }
            }
        }

        server {
            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'

            mods {
                panelsforall {
                    source sourceSets.main
                }
            }
        }
    }
}

// Include resources generated by data generators.
sourceSets.main.resources { srcDir 'src/generated/resources' }

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:1.12.2-14.23.5.2855'

    // 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"     : "panelsforall",
                "Specification-Vendor"    : "doctorspiele",
                "Specification-Version"   : "1", // We are version 1 of ourselves
                "Implementation-Title"    : project.name,
                "Implementation-Version"  : project.version,
                "Implementation-Vendor"   : "doctorspiele",
                "Implementation-Timestamp": new Date().format("yyyy-MM-dd'T'HH:mm:ssZ")
        ])
    }
}

jar.finalizedBy('reobfJar')

 

1.12 is no longer supported on this forum.

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