测试版本为Unity2017.4.25f1
1.在自定义AndroidManifest.xml(位于Assets\Plugins\Android\)中添加android:exported="true"
XML
<?xml version="1.0" encoding="utf-8"?>
<manifest
xmlns:android="http://schemas.android.com/apk/res/android"
package="com.unity3d.player"
xmlns:tools="http://schemas.android.com/tools"
android:installLocation="preferExternal"
android:versionCode="1"
android:versionName="1.0">
<supports-screens
android:smallScreens="true"
android:normalScreens="true"
android:largeScreens="true"
android:xlargeScreens="true"
android:anyDensity="true"/>
<application
android:theme="@style/UnityThemeSelector"
android:icon="@drawable/app_icon"
android:label="@string/app_name"
android:requestLegacyExternalStorage="true">
<activity android:name="com.unity3d.player.UnityPlayerActivity"
android:label="@string/app_name"
android:exported="true">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
<meta-data android:name="unityplayer.UnityActivity" android:value="true" />
</activity>
</application>
<uses-permission android:name="android.permission.ACCESS_WIFI_STATE"></uses-permission>
<uses-permission android:name="android.permission.CHANGE_WIFI_STATE"></uses-permission>
<uses-permission android:name="android.permission.INTERNET"></uses-permission>
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE"></uses-permission>
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION"></uses-permission>
<uses-permission android:name="android.permission.WRITE_SETTINGS"></uses-permission>
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />
<uses-permission android:name="android.permission.MOUNT_UNMOUNT_FILESYSTEMS" />
</manifest>
2.在菜单File>Build Settings...>PlayerSettings...>Other Settings,勾选Mute Other Audio Source*
.
3.通过以上两步应该就可以在安卓12上运行了。如果还不行就加上签名再试试。