前置き

しばらくアップデートを放置していたアプリを色々アップデートしてたら、Androidビルドでエラーになってしまう状況に……

環境

MacOS 12.6
Google Mobile Ads Unity Plugin v7.3.1
Unity 2021.3.16f1

事象

Androidビルド時に以下のようなエラー

68747470733a2f2f71696974612d696d6167652d73746f72652e73332e61702d6e6f727468656173742d312e616d617a6f6e6177732e636f6d2f302f38373731332f61663565346266382d616464612d343630332d633331332d6333663238656136356139652e706e67.png

java.io.IOException: Can't read [/Users/ユーザ名/.gradle/caches/transforms-2/files-2.1/40a5c5778e44c6cefe581fe0507a8adc/googlemobileads-unity-runtime.jar(;;;;;;;**.class)] (Can't process class [com/google/unity/ads/AdNetworkExtras.class] (Unsupported version number [55.0] (maximum 54.0, Java 10))) See the Console for details.

解決方法

Player Settings > Publishing Settings > Builsで、Custom Base Gradle Templateをチェック

1で追加された.gradleファイルを修正

allprojects {
    buildscript {
        repositories {**ARTIFACTORYREPOSITORY**
            google()
            jcenter()
            mavenCentral()  // ★★★★★追記★★★★★
        }

        dependencies {
            // If you are changing the Android Gradle Plugin version, make sure it is compatible with the Gradle version preinstalled with Unity
            // See which Gradle version is preinstalled with Unity here https://docs.unity3d.com/Manual/android-gradle-overview.html
            // See official Gradle and Android Gradle Plugin compatibility table here https://developer.android.com/studio/releases/gradle-plugin#updating-gradle
            // To specify a custom Gradle version in Unity, go do "Preferences > External Tools", uncheck "Gradle Installed with Unity (recommended)" and specify a path to a custom Gradle version
            classpath 'com.android.tools.build:gradle:4.0.1'
            classpath 'com.guardsquare:proguard-gradle:7.1.0'  // ★★★★★追記★★★★★
            **BUILD_SCRIPT_DEPS**
        }
    }

    repositories {**ARTIFACTORYREPOSITORY**
        google()
        jcenter()
        flatDir {
            dirs "${project(':unityLibrary').projectDir}/libs"
        }
    }
}

task clean(type: Delete) {
    delete rootProject.buildDir
}

そのまま再ビルド！
無事.aabファイルができた！

感想

最近Unsupported version number [55.0] (maximum 54.0, Java 10)をよく見かけるようになった気がするけど気のせい？

参考

Build Error on Android App Bundleのレス
- https://forum.unity.com/threads/build-error-on-android-app-bundle.1322166/#post-8546147