Zxing.net.mobile: Xamarin.Forms.Android app crashes only in Release mode and not in Debug Mode

[TobioDev]

Hello to everyone.
I'm making a simple app with a QRCode Scanner. When I deploy the app on my tablet (Android 4.2) in Debug Mode everything works fine.
When I deploy my app in Release Mode when I start the scanner my app crashes.
My question is: Why???

This is my code in the Forms project of Xamarin:

private async void AvviaScan(object sender, EventArgs e)
        {
#if __ANDROID__
    // Initialize the scanner first so it can track the current context
    MobileBarcodeScanner.Initialize (Application);


#endif
            var options = new ZXing.Mobile.MobileBarcodeScanningOptions();
            options.PossibleFormats = new List<ZXing.BarcodeFormat>() {
    ZXing.BarcodeFormat.QR_CODE
};
            var scanner = new ZXing.Mobile.MobileBarcodeScanner();

            var result = await scanner.Scan(options);

            if (result != null)
            {

                await Navigation.PushAsync(new Entry());

            }









        }

and here it is the exception i have in release mode:

`05-02 15:37:10.719 W/monodroid(21877): java.lang.ClassNotFoundException: Didn't find class "md5ebfcfb315379575a1b34662c6abbe082.ActivityLifecycleContextListener" on path: DexPathList[[zip file "/data/app/GKards.GKards-2.apk"],nativeLibraryDirectories=[/data/app-lib/GKards.GKards-2, /vendor/lib, /system/lib]]
05-02 15:37:10.719 W/monodroid(21877):  at dalvik.system.BaseDexClassLoader.findClass(BaseDexClassLoader.java:53)
05-02 15:37:10.719 W/monodroid(21877):  at java.lang.ClassLoader.loadClass(ClassLoader.java:501)
05-02 15:37:10.720 W/monodroid(21877):  at java.lang.ClassLoader.loadClass(ClassLoader.java:461)
05-02 15:37:10.720 W/monodroid(21877):  at md5b60ffeb829f638581ab2bb9b1a7f4f3f.ButtonRenderer_ButtonClickListener.n_onClick(Native Method)
05-02 15:37:10.720 W/monodroid(21877):  at md5b60ffeb829f638581ab2bb9b1a7f4f3f.ButtonRenderer_ButtonClickListener.onClick(ButtonRenderer_ButtonClickListener.java:29)
05-02 15:37:10.720 W/monodroid(21877):  at android.view.View.performClick(View.java:4243)
05-02 15:37:10.720 W/monodroid(21877):  at android.view.View$PerformClick.run(View.java:17520)
05-02 15:37:10.720 W/monodroid(21877):  at android.os.Handler.handleCallback(Handler.java:725)
05-02 15:37:10.720 W/monodroid(21877):  at android.os.Handler.dispatchMessage(Handler.java:92)
05-02 15:37:10.720 W/monodroid(21877):  at android.os.Looper.loop(Looper.java:153)
05-02 15:37:10.720 W/monodroid(21877):  at android.app.ActivityThread.main(ActivityThread.java:5299)
05-02 15:37:10.720 W/monodroid(21877):  at java.lang.reflect.Method.invokeNative(Native Method)
05-02 15:37:10.720 W/monodroid(21877):  at java.lang.reflect.Method.invoke(Method.java:511)
05-02 15:37:10.720 W/monodroid(21877):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:833)
05-02 15:37:10.720 W/monodroid(21877):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:600)
05-02 15:37:10.720 W/monodroid(21877):  at dalvik.system.NativeStart.main(Native Method)
Unhandled Exception:

System.TypeInitializationException: The type initializer for 'ZXing.Mobile.MobileBarcodeScanner' threw an exception.

05-02 15:37:17.392 I/MonoDroid(21877): UNHANDLED EXCEPTION:
05-02 15:37:17.394 I/MonoDroid(21877): System.TypeInitializationException: The type initializer for 'ZXing.Mobile.MobileBarcodeScanner' threw an exception. ---> Java.Lang.ClassNotFoundException: Didn't find class "md5ebfcfb315379575a1b34662c6abbe082.ActivityLifecycleContextListener" on path: DexPathList[[zip file "/data/app/GKards.GKards-2.apk"],nativeLibraryDirectories=[/data/app-lib/GKards.GKards-2, /vendor/lib, /system/lib]]
05-02 15:37:17.394 I/MonoDroid(21877):   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw () [0x0000c] in /Users/builder/data/lanes/3053/a94a03b5/source/mono/external/referencesource/mscorlib/system/runtime/exceptionservices/exceptionservicescommon.cs:143 
05-02 15:37:17.394 I/MonoDroid(21877):   at Android.Runtime.JNIEnv.CallObjectMethod (IntPtr jobject, IntPtr jmethod, Android.Runtime.JValue* parms) [0x00064] in /Users/builder/data/lanes/3053/a94a03b5/source/monodroid/src/Mono.Android/src/Runtime/JNIEnv.g.cs:195 
05-02 15:37:17.394 I/MonoDroid(21877):   at Android.Runtime.JNIEnv.CallObjectMethod (IntPtr jobject, IntPtr jmethod, Android.Runtime.JValue[] parms) [0x0001d] in /Users/builder/data/lanes/3053/a94a03b5/source/monodroid/src/Mono.Android/src/Runtime/JNIEnv.g.cs:203 
05-02 15:37:17.394 I/MonoDroid(21877):   at Android.Runtime.JNIEnv.FindClass (System.String classname) [0x00007] in /Users/builder/data/lanes/3053/a94a03b5/source/monodroid/src/Mono.Android/src/Runtime/JNIEnv.cs:494 
05-02 15:37:17.394 I/MonoDroid(21877):   at Android.Runtime.JNIEnv.FindClass (System.Type type) [0x00009] in /Users/builder/data/lanes/3053/a94a03b5/source/monodroid/src/Mono.Android/src/Runtime/JNIEnv.cs:434 
05-02 15:37:17.394 I/MonoDroid(21877):   --- End of managed exception stack trace ---
05-02 15:37:17.394 I/MonoDroid(21877): java.lang.ClassNotFoundException: Didn't find class "md5ebfcfb315379575a1b34662c6abbe082.ActivityLifecycleContextListener" on path: DexPathList[[zip file "/data/app/GKards.GKards-2.apk"],nativeLibraryDirectories=[/data/app-lib/GKards.GKards-2, /vendor/lib, /system/lib]]
05-02 15:37:17.394 I/MonoDroid(21877):  at dalvik.system.BaseDexClassLoader.findClass(BaseDexClassLoader.java:53)
05-02 15:37:17.394 I/MonoDroid(21877):  at java.lang.ClassLoader.loadClass(ClassLoader.java:501)
05-02 15:37:17.394 I/MonoDroid(21877):  at java.lang.ClassLoader.loadClass(ClassLoader.java:461)
05-02 15:37:17.394 I/MonoDroid(21877):  at md5b60ffeb829f638581ab2bb9b1a7f4f3f.ButtonRenderer_ButtonClickListener.n_onClick(Native Method)
05-02 15:37:17.394 I/MonoDroid(21877):  at md5b60ffeb829f638581ab2bb9b1a7f4f3f.ButtonRenderer_ButtonClickListener.onClick(ButtonRenderer_ButtonClickListener.java:29)
05-02 15:37:17.394 I/MonoDroid(21877):  at android.view.View.performClick(View.java:4243)
05-02 15:37:17.394 I/MonoDroid(21877):  at android.view.View$PerformClick.run(View.java:17520)
05-02 15:37:17.394 I/MonoDroid(21877):  at android.os.Handler.handleCallback(Handler.java:725)
05-02 15:37:17.394 I/MonoDroid(21877):  at android.os.Handler.dispatchMessage(Handler.java:92)
05-02 15:37:17.394 I/MonoDroid(21877):  at android.os.Looper.loop(Looper.java:153)
05-02 15:37:17.394 I/MonoDroid(21877):  at android.app.ActivityThread.main(ActivityThread.java:5299)
05-02 15:37:17.394 I/MonoDroid(21877):  at java.lang.reflect.Method.invokeNative(Native Method)
05-02 15:37:17.394 I/MonoDroid(21877):  at java.lang.reflect.Method.invoke(Method.java:511)
05-02 15:37:17.394 I/MonoDroid(21877):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:833)
05-02 15:37:17.394 I/MonoDroid(21877):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:600)
05-02 15:37:17.395 I/MonoDroid(21877):  at dalvik.system.NativeStart.main(Native Method)
05-02 15:37:17.395 I/MonoDroid(21877):   --- End of inner exception stack trace ---
05-02 15:37:17.395 I/MonoDroid(21877):   at GKards.Scan+<AvviaScan>d__1.MoveNext () [0x00045] in C:\Users\ospite\Documents\GKards2\GKards\GKards\Scan.xaml.cs:61 
05-02 15:37:17.395 I/MonoDroid(21877): --- End of stack trace from previous location where exception was thrown ---
05-02 15:37:17.395 I/MonoDroid(21877):   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw () [0x0000c] in /Users/builder/data/lanes/3053/a94a03b5/source/mono/external/referencesource/mscorlib/system/runtime/exceptionservices/exceptionservicescommon.cs:143 
05-02 15:37:17.395 I/MonoDroid(21877):   at System.Runtime.CompilerServices.AsyncMethodBuilderCore.<ThrowAsync>m__0 (System.Object state) [0x00000] in /Users/builder/data/lanes/3053/a94a03b5/source/mono/external/referencesource/mscorlib/system/runtime/compilerservices/AsyncMethodBuilder.cs:994 
05-02 15:37:17.395 I/MonoDroid(21877):   at Android.App.SyncContext+<Post>c__AnonStorey0.<>m__0 () [0x00000] in /Users/builder/data/lanes/3053/a94a03b5/source/monodroid/src/Mono.Android/src/Android.App/SyncContext.cs:18 
05-02 15:37:17.395 I/MonoDroid(21877):   at Java.Lang.Thread+RunnableImplementor.Run () [0x0000b] in /Users/builder/data/lanes/3053/a94a03b5/source/monodroid/src/Mono.Android/src/Java.Lang/Thread.cs:36 
05-02 15:37:17.395 I/MonoDroid(21877):   at Java.Lang.IRunnableInvoker.n_Run (IntPtr jnienv, IntPtr native__this) [0x00009] in /Users/builder/data/lanes/3053/a94a03b5/source/monodroid/src/Mono.Android/platforms/android-23/src/generated/Java.Lang.IRunnable.cs:71 
05-02 15:37:17.395 I/MonoDroid(21877):   at (wrapper dynamic-method) System.Object:c988d302-b863-4aa0-9ae6-8189378b1b6f (intptr,intptr)
05-02 15:37:17.410 I/dalvikvm(21877): Could not find method java.lang.Throwable.<init>, referenced from method md52ce486a14f4bcd95899665e9d932190b.JavaProxyThrowable.<init>
05-02 15:37:17.410 W/dalvikvm(21877): VFY: unable to resolve direct method 17744: Ljava/lang/Throwable;.<init> (Ljava/lang/String;Ljava/lang/Throwable;ZZ)V
05-02 15:37:17.410 D/dalvikvm(21877): VFY: replacing opcode 0x70 at 0x0000
An unhandled exception occured.

05-02 15:37:18.493 E/mono    (21877): 
05-02 15:37:18.493 E/mono    (21877): Unhandled Exception:
05-02 15:37:18.493 E/mono    (21877): System.TypeInitializationException: The type initializer for 'ZXing.Mobile.MobileBarcodeScanner' threw an exception. ---> Java.Lang.ClassNotFoundException: Didn't find class "md5ebfcfb315379575a1b34662c6abbe082.ActivityLifecycleContextListener" on path: DexPathList[[zip file "/data/app/GKards.GKards-2.apk"],nativeLibraryDirectories=[/data/app-lib/GKards.GKards-2, /vendor/lib, /system/lib]]
05-02 15:37:18.493 E/mono    (21877):   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw () [0x0000c] in /Users/builder/data/lanes/3053/a94a03b5/source/mono/external/referencesource/mscorlib/system/runtime/exceptionservices/exceptionservicescommon.cs:143 
05-02 15:37:18.493 E/mono    (21877):   at Android.Runtime.JNIEnv.CallObjectMethod (IntPtr jobject, IntPtr jmethod, Android.Runtime.JValue* parms) [0x00064] in /Users/builder/data/lanes/3053/a94a03b5/source/monodroid/src/Mono.Android/src/Runtime/JNIEnv.g.cs:195 
05-02 15:37:18.493 E/mono    (21877):   at Android.Runtime.JNIEnv.CallObjectMethod (IntPtr jobject, IntPtr jmethod, Android.Runtime.JValue[] parms) [0x0001d] in /Users/builder/data/lanes/3053/a94a03b5/source/monodroid/src/Mono.Android/src/Runtime/JNIEnv.g.cs:203 
05-02 15:37:18.493 E/mono    (21877):   at Android.Runtime.JNIEnv.FindClass (System.String classname) [0x00007] in /Users/builder/data/lanes/3053/a94a03b5/source/monodroid/src/Mono.Android/src/Runtime/JNIEnv.cs:494 
05-02 15:37:18.493 E/mono    (21877):   at Android.Runtime.JNIEnv.FindClass (System.Type type) [0x00009] in /Users/builder/data/lanes/3053/a94a03b5/source/monodroid/src/Mono.Android/src/Runtime/JNIEnv.cs:434 
05-02 15:37:18.493 E/mono    (21877):   --- End of managed exception stack trace ---
05-02 15:37:18.493 E/mono    (21877): java.lang.ClassNotFoundException: Didn't find class "md5ebfcfb315379575a1b34662c6abbe082.ActivityLifecycleContextListener" on path: DexPathList[[zip file "/data/app/GKards.GKards-2.apk"],nativeLibraryDirectories=[/data/app-lib/GKards.GKards-2, /vendor/lib, /system/lib]]
05-02 15:37:18.493 E/mono    (21877):   at dalvik.system.BaseDexClassLoader.findClass(BaseDexClassLoader.java:53)
05-02 15:37:18.493 E/mono    (21877):   at java.lang.ClassLoader.loadClass(ClassLoader.java:501)
05-02 15:37:18.493 E/mono    (21877):   at java.lang.ClassLoader.loadClass(ClassLoader.java:461)
05-02 15:37:18.493 E/mono    (21877):   at md5b60ffeb829f638581ab2bb9b1a7f4f3f.ButtonRenderer_ButtonClickListener.n_onClick(Native Method)
05-02 15:37:18.493 E/mono    (21877):   at md5b60ffeb829f638581ab2bb9b1a7f4f3f.ButtonRenderer_ButtonClickListener.onClick(ButtonRenderer_ButtonClickListener.java:29)
05-02 15:37:18.493 E/mono    (21877):   at android.view.View.performClick(View.java:4243)
05-02 15:37:18.493 E/mono    (21877):   at android.view.View$PerformClick.run(View.java:17520)
05-02 15:37:18.493 E/mono    (21877):   at android.os.Handler.handleCallback(Handler.java:725)
05-02 15:37:18.493 E/mono    (21877):   at android.os.Handler.dispatchMessage(Handler.java:92)
05-02 15:37:18.493 E/mono    (21877):   at android.os.Looper.loop(Looper.java:153)
05-02 15:37:18.493 E/mono    (21877):   at android.app.ActivityThread.main(ActivityThread.java:5299)
05-02 15:37:18.493 E/mono    (21877):   at java.lang.reflect.Method.invokeNative(Native Method)
05-02 15:37:18.493 E/mono    (21877):   at java.lang.reflect.Method.invoke(Method.java:511)
05-02 15:37:18.493 E/mono    (21877):   at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:833)
05-02 15:37:18.493 E/mono    (21877):   at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:600)
05-02 15:37:18.493 E/mono    (21877):   at dalvik.system.NativeStart.main(Native Method)
05-02 15:37:18.493 E/mono    (21877): 
05-02 15:37:18.493 E/mono    (21877):   --- End of inner exception stack trace ---
05-02 15:37:18.493 E/mono    (21877):   at GKards.Scan+<AvviaScan>d__1.MoveNext () [0x00045] in C:\Users\ospite\Documents\GKards2\GKards\GKards\Scan.xaml.cs:61 
05-02 15:37:18.493 E/mono    (21877): --- End of stack trace from previous location where exception was thrown ---
05-02 15:37:18.493 E/mono    (21877):   at (wrapper dynamic-method) System.Object:c988d302-b863-4aa0-9ae6-8189378b1b6f (intptr,intptr)
05-02 15:37:18.493 E/mono    (21877):   at (wrapper native-to-managed) System.Object:c988d302-b863-4aa0-9ae6-8189378b1b6f (intptr,intptr)
05-02 15:37:18.494 E/mono-rt (21877): [ERROR] FATAL UNHANDLED EXCEPTION: System.TypeInitializationException: The type initializer for 'ZXing.Mobile.MobileBarcodeScanner' threw an exception. ---> Java.Lang.ClassNotFoundException: Didn't find class "md5ebfcfb315379575a1b34662c6abbe082.ActivityLifecycleContextListener" on path: DexPathList[[zip file "/data/app/GKards.GKards-2.apk"],nativeLibraryDirectories=[/data/app-lib/GKards.GKards-2, /vendor/lib, /system/lib]]
05-02 15:37:18.494 E/mono-rt (21877):   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw () [0x0000c] in /Users/builder/data/lanes/3053/a94a03b5/source/mono/external/referencesource/mscorlib/system/runtime/exceptionservices/exceptionservicescommon.cs:143 
05-02 15:37:18.494 E/mono-rt (21877):   at Android.Runtime.JNIEnv.CallObjectMethod (IntPtr jobject, IntPtr jmethod, Android.Runtime.JValue* parms) [0x00064] in /Users/builder/data/lanes/3053/a94a03b5/source/monodroid/src/Mono.Android/src/Runtime/JNIEnv.g.cs:195 
05-02 15:37:18.494 E/mono-rt (21877):   at Android.Runtime.JNIEnv.CallObjectMethod (IntPtr jobject, IntPtr jmethod, Android.Runtime.JValue[] parms) [0x0001d] in /Users/builder/data/lanes/3053/a94a03b5/source/monodroid/src/Mono.Android/src/Runtime/JNIEnv.g.cs:203 
05-02 15:37:18.494 E/mono-rt (21877):   at Android.Runtime.JNIEnv.FindClass (System.String classname) [0x00007] in /Users/builder/data/lanes/3053/a94a03b5/source/monodroid/src/Mono.Android/src/Runtime/JNIEnv.cs:494 
05-02 15:37:18.494 E/mono-rt (21877):   at Android.Runtime.JNIEnv.FindClass (System.Type type) [0x00009] in /Users/builder/data/lanes/3053/a94a03b5/source/monodroid/src/Mono.Android/src/Runtime/JNIEnv.cs:434 
05-02 15:37:18.494 E/mono-rt (21877):   --- End of managed exception stack trace ---
05-02 15:37:18.494 E/mono-rt (21877): java.lang.ClassNotFoundException: Didn't find class "md5ebfcfb315379575a1b34662c6abbe082.ActivityLifecycleContextListener" on path: DexPathList[[zip file "/data/app/GKards.GKards-2.apk"],nativeLibraryDirectories=[/data/app-lib/GKards.GKards-2, /vendor/lib, /system/lib]]
05-02 15:37:18.494 E/mono-rt (21877):   at dalvik.system.BaseDexClassLoader.findClass(BaseDexClassLoader.java:53)
05-02 15:37:18.494 E/mono-rt (21877):   at java.lang.ClassLoader.loadClass(ClassLoader.java:501)
05-02 15:37:18.494 E/mono-rt (21877):   at java.lang.ClassLoader.loadClass(ClassLoader.java:461)
05-02 15:37:18.494 E/mono-rt (21877):   at md5b60ffeb829f638581ab2bb9b1a7f4f3f.ButtonRenderer_ButtonClickListener.n_onClick(Native Method)
05-02 15:37:18.494 E/mono-rt (21877):   at md5b60ffeb829f638581ab2bb9b1a7f4f3f.ButtonRenderer_ButtonClickListener.onClick(ButtonRenderer_ButtonClickListener.java:29)
05-02 15:37:18.494 E/mono-rt (21877):   at android.view.View.performClick(View.java:4243)
05-02 15:37:18.494 E/mono-rt (21877):   at android.view.View$PerformClick.run(View.java:17520)
05-02 15:37:18.494 E/mono-rt (21877):   at android.os.Handler.handleCallback(Handler.java:725)
05-02 15:37:18.494 E/mono-rt (21877):   at android.os.Handler.dispatchMessage(Handler.java:92)
05-02 15:37:18.494 E/mono-rt (21877):   at android.os.Looper.loop(Looper.java:153)
05-02 15:37:18.494 E/mono-rt (21877):   at android.app.ActivityThread.main(ActivityThread.java:5299)
05-02 15:37:18.494 E/mono-rt (21877):   at java.lang.reflect.Method.invokeNative(Native Method)
05-02 15:37:18.494 E/mono-rt (21877):   at java.lang.reflect.Method.invoke(Method.java:511)
05-02 15:37:18.494 E/mono-rt (21877):   at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:833)
05-02 15:37:18.494 E/mono-rt (21877):   at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:600)
05-02 15:37:18.494 E/mono-rt (21877):   at dalvik.system.NativeStart.main(Native Method)
05-02 15:37:18.494 E/mono-rt (21877): 
05-02 15:37:18.494 E/mono-rt (21877):   --- End of inner exception stack trace ---
05-02 15:37:18.494 E/mono-rt (21877):   at GKards.Scan+<AvviaScan>d__1.MoveNext () [0x00045] in C:\Users\ospite\Documents\GKards2\GKards\GKards\Scan.xaml.cs:61 
05-02 15:37:18.494 E/mono-rt (21877): --- End of stack trace from previous location where exception was thrown ---
05-02 15:37:18.494 E/mono-rt (21877):   at (wrapper dynamic-method) System.Object:c988d302-b863-4aa0-9ae6-8189378b1b6f (intptr,intptr)
05-02 15:37:18.494 E/mono-rt (21877):   at (wrapper native-to-managed) System.Object:c988d302-b863-4aa0-9ae6-8189378b1b6f (intptr,intptr)
05-02 15:37:18.578 I/IspDrv  (21877): {IspDrv} [~IspDrvImp] 

Thanks to everyone in advantage for helping me!! :)

[redwolf2]

Solution 1: Uninstall your local app that was deployed under Debug mode manually. Deploy Release app.
Solution 2: Update your version of Xamarin
Solution 3: Project setting → Android Options → Linker → Konfiguration = Release; Linking = Sdk Assemblys Only

[shanta-goswami]

If your solution works in Debug mode, but not in Release mode, it might be an issue with the Linker.

Right Click on your specific project (not Solution) -> Android Options -> Linker -> Choose "None" in Linking. This will include all dlls in the Release Library.

[huxaiphaer]

@shanta-goswami , but this will make the Apk too big

[iyepes]

In case this could be useful still. I just had the same problem. The solution was keeping Linking SDKs Assemblys Only and Disable Proguard. It was Proward that caused the issue.