안드로이드 스튜디오 앱중지 반복

Question

제가 애드몹 광고를 넣었는데 오류가 뜨고 앱을 실행하면 실행이 안됩니다 도와주세요 ㅠ

E/AndroidRuntime: FATAL EXCEPTION: main
    Process: info.soundeffect.effect, PID: 32653
    java.lang.RuntimeException: Unable to instantiate activity ComponentInfo{info.soundeffect.effect/com.example.effects.info.example.effects.MainActivity}: java.lang.ClassNotFoundException: Didn't find class "com.example.effects.info.example.effects.MainActivity" on path: DexPathList[[zip file "/data/app/info.soundeffect.effect-ZmW73GKhoQ2VYt4GJGX0kA==/base.apk"],nativeLibraryDirectories=[/data/app/info.soundeffect.effect-ZmW73GKhoQ2VYt4GJGX0kA==/lib/x86, /system/lib, /system/product/lib]]
        at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:3194)
        at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:3409)
        at android.app.servertransaction.LaunchActivityItem.execute(LaunchActivityItem.java:83)
        at android.app.servertransaction.TransactionExecutor.executeCallbacks(TransactionExecutor.java:135)
        at android.app.servertransaction.TransactionExecutor.execute(TransactionExecutor.java:95)
        at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2016)
        at android.os.Handler.dispatchMessage(Handler.java:107)
        at android.os.Looper.loop(Looper.java:214)
        at android.app.ActivityThread.main(ActivityThread.java:7356)
        at java.lang.reflect.Method.invoke(Native Method)
        at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:492)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:930)
     Caused by: java.lang.ClassNotFoundException: Didn't find class "com.example.effects.info.example.effects.MainActivity" on path: DexPathList[[zip file "/data/app/info.soundeffect.effect-ZmW73GKhoQ2VYt4GJGX0kA==/base.apk"],nativeLibraryDirectories=[/data/app/info.soundeffect.effect-ZmW73GKhoQ2VYt4GJGX0kA==/lib/x86, /system/lib, /system/product/lib]]
        at dalvik.system.BaseDexClassLoader.findClass(BaseDexClassLoader.java:196)
        at java.lang.ClassLoader.loadClass(ClassLoader.java:379)
        at java.lang.ClassLoader.loadClass(ClassLoader.java:312)
        at android.app.AppComponentFactory.instantiateActivity(AppComponentFactory.java:95)
        at androidx.core.app.CoreComponentFactory.instantiateActivity(CoreComponentFactory.java:43)
        at android.app.Instrumentation.newActivity(Instrumentation.java:1243)
        at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:3182)
        at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:3409)
        at android.app.servertransaction.LaunchActivityItem.execute(LaunchActivityItem.java:83)
        at android.app.servertransaction.TransactionExecutor.executeCallbacks(TransactionExecutor.java:135)
        at android.app.servertransaction.TransactionExecutor.execute(TransactionExecutor.java:95)
        at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2016)
        at android.os.Handler.dispatchMessage(Handler.java:107)
        at android.os.Looper.loop(Looper.java:214)
        at android.app.ActivityThread.main(ActivityThread.java:7356)
        at java.lang.reflect.Method.invoke(Native Method)
        at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:492)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:930)