Java, Android Studio, Gradle, LibGDX, KryoNet - Error: Program type already present: com.esotericsoftware.jsonbeans.Json$Serializer

Question

This problem popped up out of nowhere on me and it only affects the Android project and building an APK.

I'm not entirely sure what the problem is. I spent the better part of last night on Google trying to find something, anything, out. I got nowhere with it, so here I am.

Here is the project's overall gradle.build file:

buildscript {


    repositories {
        mavenLocal()
        mavenCentral()
        maven { url "https://oss.sonatype.org/content/repositories/snapshots/" }
        google()
        jcenter()
    }
    dependencies {
        classpath 'com.android.tools.build:gradle:3.3.1'
        classpath 'com.mobidevelop.robovm:robovm-gradle-plugin:2.3.1'
    }
}

allprojects {
    apply plugin: "eclipse"
    apply plugin: "idea"

    version = ""
    ext {
        appName = "fade-online"
        gdxVersion = '1.9.8'
        roboVMVersion = '2.3.1'
        box2DLightsVersion = '1.4'
        ashleyVersion = '1.7.0'
        aiVersion = '1.8.0'
    }

    repositories {
        mavenLocal()
        mavenCentral()
        maven { url "https://oss.sonatype.org/content/repositories/snapshots/" }
        maven { url "https://oss.sonatype.org/content/repositories/releases/" }
        google()
        jcenter()
    }
}

project(":desktop") {
    apply plugin: "java"


    dependencies {
        implementation project(":core")
        implementation "com.badlogicgames.gdx:gdx-backend-lwjgl:$gdxVersion"
        implementation "com.badlogicgames.gdx:gdx-platform:$gdxVersion:natives-desktop"

    }
}

project(":rtoserver") {
    apply plugin: "java"

    dependencies {
        implementation "com.badlogicgames.gdx:gdx-backend-lwjgl:$gdxVersion"
        implementation "com.badlogicgames.gdx:gdx-platform:$gdxVersion:natives-desktop"
    }
}

project(":editorsuite") {
    apply plugin: "java"

    dependencies {
        implementation project(":core")
        implementation "com.badlogicgames.gdx:gdx-backend-lwjgl:$gdxVersion"
        implementation "com.badlogicgames.gdx:gdx-platform:$gdxVersion:natives-desktop"
    }
}

project(":android") {
    apply plugin: "android"

    configurations { natives }

    android {
        dexOptions {
            preDexLibraries = false
        }
    }

    dependencies {
        implementation project(":core")
        implementation "com.badlogicgames.gdx:gdx-backend-android:$gdxVersion"
        natives "com.badlogicgames.gdx:gdx-platform:$gdxVersion:natives-armeabi"
        natives "com.badlogicgames.gdx:gdx-platform:$gdxVersion:natives-armeabi-v7a"
        natives "com.badlogicgames.gdx:gdx-platform:$gdxVersion:natives-arm64-v8a"
        natives "com.badlogicgames.gdx:gdx-platform:$gdxVersion:natives-x86"
        natives "com.badlogicgames.gdx:gdx-platform:$gdxVersion:natives-x86_64"

    }
}

project(":ios") {
    apply plugin: "java"
    apply plugin: "robovm"


    dependencies {
        implementation project(":core")
        implementation "com.mobidevelop.robovm:robovm-rt:$roboVMVersion"
        implementation "com.mobidevelop.robovm:robovm-cocoatouch:$roboVMVersion"
        implementation "com.badlogicgames.gdx:gdx-backend-robovm:$gdxVersion"
        implementation "com.badlogicgames.gdx:gdx-platform:$gdxVersion:natives-ios"

    }
}

project(":core") {
    apply plugin: "java"


    dependencies {
        implementation "com.badlogicgames.gdx:gdx:$gdxVersion"
    }
}

tasks.eclipse.doLast {
    delete ".project"
}

Here is my gradle.build file for the Android project:

    android {
    buildToolsVersion '28.0.3'
    compileSdkVersion 28
    sourceSets {
        main {
            manifest.srcFile 'AndroidManifest.xml'
            java.srcDirs = ['src']
            aidl.srcDirs = ['src']
            renderscript.srcDirs = ['src']
            res.srcDirs = ['res']
            assets.srcDirs = ['assets']
            jniLibs.srcDirs = ['libs']
        }
    }
    packagingOptions {
        exclude 'META-INF/robovm/ios/robovm.xml'
    }
    defaultConfig {
        applicationId "com.forgottenartsstudios.fadeonline"
        minSdkVersion 24
        targetSdkVersion 28
        versionCode 7
        versionName '0.7.000'
    }
    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
        }
    }
    compileOptions {
        sourceCompatibility JavaVersion.VERSION_1_8
        targetCompatibility JavaVersion.VERSION_1_8
    }
    productFlavors {
    }
}

task copyAndroidNatives() {
    file("libs/armeabi/").mkdirs()
    file("libs/armeabi-v7a/").mkdirs()
    file("libs/arm64-v8a/").mkdirs()
    file("libs/x86_64/").mkdirs()
    file("libs/x86/").mkdirs()

    configurations.natives.files.each { jar ->
        def outputDir = null
        if (jar.name.endsWith("natives-arm64-v8a.jar")) outputDir = file("libs/arm64-v8a")
        if (jar.name.endsWith("natives-armeabi-v7a.jar")) outputDir = file("libs/armeabi-v7a")
        if (jar.name.endsWith("natives-armeabi.jar")) outputDir = file("libs/armeabi")
        if (jar.name.endsWith("natives-x86_64.jar")) outputDir = file("libs/x86_64")
        if (jar.name.endsWith("natives-x86.jar")) outputDir = file("libs/x86")
        if (outputDir != null) {
            copy {
                from zipTree(jar)
                into outputDir
                include "*.so"
            }
        }
    }
}
task run(type: Exec) {
    def path
    def localProperties = project.file("../local.properties")
    if (localProperties.exists()) {
        Properties properties = new Properties()
        localProperties.withInputStream { instr ->
            properties.load(instr)
        }
        def sdkDir = properties.getProperty('sdk.dir')
        if (sdkDir) {
            path = sdkDir
        } else {
            path = "$System.env.ANDROID_HOME"
        }
    } else {
        path = "$System.env.ANDROID_HOME"
    }

    def adb = path + "/platform-tools/adb"
    commandLine "$adb", 'shell', 'am', 'start', '-n', 'com.forgottenartsstudios.fadeonline/com.forgottenartsstudios.fadeonline.AndroidLauncher'
}
eclipse {

    sourceSets {
        main {
            java.srcDirs "src", 'gen'
        }
    }

    jdt {
        sourceCompatibility = 1.8
        targetCompatibility = 1.8
    }

    classpath {
        plusConfigurations += [project.configurations.compile]
        containers 'com.android.ide.eclipse.adt.ANDROID_FRAMEWORK', 'com.android.ide.eclipse.adt.LIBRARIES'
    }

    project {
        name = appName + "-android"
        natures 'com.android.ide.eclipse.adt.AndroidNature'
        buildCommands.clear()
        buildCommand "com.android.ide.eclipse.adt.ResourceManagerBuilder"
        buildCommand "com.android.ide.eclipse.adt.PreCompilerBuilder"
        buildCommand "org.eclipse.jdt.core.javabuilder"
        buildCommand "com.android.ide.eclipse.adt.ApkBuilder"
    }
}
idea {
    module {
        sourceDirs += file("src")
        scopes = [COMPILE: [plus: [project.configurations.compile]]]

        iml {
            withXml {
                def node = it.asNode()
                def builder = NodeBuilder.newInstance()
                builder.current = node
                builder.component(name: "FacetManager") {
                    facet(type: "android", name: "Android") {
                        configuration {
                            option(name: "UPDATE_PROPERTY_FILES", value: "true")
                        }
                    }
                }
            }
        }
    }
}
dependencies {
    implementation files('libs/kryonet-2.21-all.jar')
}

Here's the Core gradle.build file:

apply plugin: "java"
sourceCompatibility = 1.8
[compileJava, compileTestJava]*.options*.encoding = 'UTF-8'
sourceSets.main.java.srcDirs = ["src/"]
eclipse.project {
    name = appName + "-core"
}
dependencies {
    implementation files('libs/kryonet-2.21-all.jar')
    implementation project(':rtoserver')
}

Here's the Server gradle.build file:

apply plugin: 'java'

dependencies {
    implementation files('libs/kryonet-2.21-all.jar')
    implementation 'com.badlogicgames.gdx:gdx:1.9.8'
}

sourceCompatibility = "1.8"
targetCompatibility = "1.8"

And here's the Desktop gradle.build file:

apply plugin: "java"
sourceCompatibility = 1.8
sourceSets.main.java.srcDirs = ["src/"]
project.ext.mainClassName = "com.forgottenartsstudios.fadeonline.desktop.DesktopLauncher"
project.ext.assetsDir = new File("../android/assets")
task run(dependsOn: classes, type: JavaExec) {
    main = project.mainClassName
    classpath = sourceSets.main.runtimeClasspath
    standardInput = System.in
    workingDir = project.assetsDir
    ignoreExitValue = true
}
task debug(dependsOn: classes, type: JavaExec) {
    main = project.mainClassName
    classpath = sourceSets.main.runtimeClasspath
    standardInput = System.in
    workingDir = project.assetsDir
    ignoreExitValue = true
    debug = true
}
task dist(type: Jar) {
    from files(sourceSets.main.output.classesDir)
    from files(sourceSets.main.output.resourcesDir)
    from { configurations.compile.collect { zipTree(it) } }
    from files(project.assetsDir)

    baseName = "FADEOnline"

    manifest {
        attributes 'Main-Class': project.mainClassName
    }
}
dist.dependsOn classes
eclipse {
    project {
        name = appName + "-desktop"
        linkedResource name: 'assets', type: '2', location: 'PARENT-1-PROJECT_LOC'
    }
}
task afterEclipseImport(description: "Post processing after project generation", group: "IDE") {
    doLast {
        def classpath = new XmlParser().parse(file(".classpath"))
        new Node(classpath, "classpathentry", [kind: 'src', path: 'assets'])
        def writer = new FileWriter(file(".classpath"))
        def printer = new XmlNodePrinter(new PrintWriter(writer))
        printer.setPreserveWhitespace(true)
        printer.print(classpath)
    }
}

dependencies {
    implementation project(path: ':android', configuration: 'default')
}

I'm fairly new to StackOverflow, so I apologize for anything I do wrong.

If you need more information, please let me know and I will provide it as soon as possible.

Thank you.