Develop Reference

App crashes when downloaded from Google Play

I've just built and deployed an app to Google Play. It worked well when I was running it through Android Studio but now it crashes when I download it from Google Play. Because this is my first time, I don't even know how to view the crash report/stacktrace of the app that was downloaded from Google Play. I appreciate any and all help.
UPDATE
So I got the stacktrace for the APK. It tells me that my TopImageFragment.java class cannot create my MemeViewModel.java class. I have no clue why its giving this error. Everything works fine as it is. It seems that proguard is indeed phasing out an important class:
2019-04-18 00:46:32.062 8099-8099/? E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.ozbek.onur.memegenerator, PID: 8099
java.lang.RuntimeException: Unable to start activity ComponentInfo{com.ozbek.onur.memegenerator/com.ozbek.onur.memegenerator.MainActivity}: java.lang.RuntimeException: Cannot create an instance of class com.ozbek.onur.memegenerator.MemeViewModel
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2853)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2928)
at android.app.ActivityThread.-wrap11(Unknown Source:0)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1609)
at android.os.Handler.dispatchMessage(Handler.java:105)
at android.os.Looper.loop(Looper.java:164)
at android.app.ActivityThread.main(ActivityThread.java:6703)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.Zygote$MethodAndArgsCaller.run(Zygote.java:240)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:769)
Caused by: java.lang.RuntimeException: Cannot create an instance of class com.ozbek.onur.memegenerator.MemeViewModel
at android.arch.lifecycle.ViewModelProvider$NewInstanceFactory.create(ViewModelProvider.java:155)
at android.arch.lifecycle.ViewModelProvider$AndroidViewModelFactory.create(ViewModelProvider.java:210)
at android.arch.lifecycle.ViewModelProvider.get(ViewModelProvider.java:134)
at android.arch.lifecycle.ViewModelProvider.get(ViewModelProvider.java:102)
at com.ozbek.onur.memegenerator.TopImageFragment.onActivityCreated(TopImageFragment.java:89)

This kind of problem usually happens because your app deployed to Google Play was a release build and proguard minified your app and removed a class it shouldn't have. When you build in Android Studio it is a debug build that does not get minified. That's why you see the crash only from Google Play.
Before uploading to Google Play, test out your release APK file on a device and watch logcat for the error. That should tell you what class got removed by mistake and you can correct that by specifying custom proguard rules and trying again until the app stops crashing. Then when you upload to Google Play, you should be good.
You can also enable proguard in a debug build as well by changing your build.gradle file. Then when you run through Android Studio, you should see the same error as you see through Google Play.
One other alternative, you can disable proguard/minification in your release build. However this is not recommended because your app will be larger than it needs to be.

Check if you have any java files that don't have an access modifier. In my experience, just declaring a class without a public or private modifier, causes this problem.

My app suffered the same problem and it was a ProGuard kill.
Because ProGuard renames all classes unless otherwise instructed.
So, in your case, you have to add
#Keep
annotation before your class name MemeViewModel.
example,
#Keep
class MemeViewModel{
//
//
}

In my suggestion, keep your phone connected to your your PC/Laptop while you download and attempt to open it. Use Logcat on android studio, it mostly has all answers or at least errors that lead to the answers. try putting error logs here so we can have a proper look at it.
1) Try the same version of your application that you deployed on Google play store by pushing it through the android studio and see if the problem continues!
2) If same thing happens then put breakpoint on the entry point (onCreate method in most cases in MainActivity class) of your application and Go to Run->Debug "YourProject" option and do step by step debug for each command being executed and see which one is causing problem.

Unable to instantiate receiver com.google.android.apps.analytics.AnalyticsReceiver

I have uploaded the Android app into playstore. While downloading it for the first time it gets crashed but after that it works fine. Its showing the error as Unable to instantiate receiver com.google.android.apps.analytics.AnalyticsReceiver Caused by java.lang.ClassNotFoundException: Didn't find class "com.google.android.apps.analytics.AnalyticsReceiver" .
How to resolve this issue?

I believe that issue related to your manifest file and refer to INSTALL_REFERRER.
Make sure if AnalyticsReceiver class included to your app
My suggestion, if you not use that receiver you can remove it, otherwise will keep throw crash error
Note:
As far as I know com.google.android.apps.analytics.AnalyticsReceiver from Google Analytics SDK v3
While if you using Google Analytics SDK v4 you should use com.google.android.gms.analytics.CampaignTrackingReceiver
Please read this post too

Android application signed with same key store using same sharedUserId crashes due to java.lang.RuntimeException: Unable to instantiate activity

I want to make some Android applications running in the same process, so I give those apps's AndroidManifest the same sharedUserId:
< manifest xmlns:android="http://schemas.android.com/apk/res/android"
...
android:sharedUserId="aaa.bbb" >
and assign each apps's application the same process:
< application
...
android:process="com.mytest" >
It works in android 4.4.4 , all the Applications run in the same Process.
But crash happened in android 6.0.1.
When I run the second app, it crashes due to:
java.lang.RuntimeException: Unable to instantiate activity ComponentInfo{com.example.myapplication/com.example.myapplication.MainActivity}:
java.lang.ClassNotFoundException: Didn't find class "com.example.myapplication.MainActivity" on path:
DexPathList[[zip file "/data/app/com.example.myapplication-1/base.apk"],nativeLibraryDirectories=[/data/app/com.example.myapplication-1/lib/arm, /vendor/lib, /system/lib]]
after the system kill the Process, the second app can run and crashes if I run the first application.
It seem that applications can not run in the same process in the same time and I do not know why.

Each APK has its own ClassLoader. An article talking about this.
So it's normal you can't access a class of another APK.
It seems that a security bug was fix between Kitkat and Marshmallow.
Why you need this system ?
If it's to share data between application, you could use ContentProvider
If it's to launch Activity or Service, you could use Intent with action.

I fixed it !
disable the options in Android studio ant it works !

GCM push noti in Unity3d causes gms.iid.InstanceID classnotfound

I have made an Android plugin to use GCM in my Unity app. When I try to start the RegistrationIntentService (readymade example class from Android Developer Manual site), it causes a crash with the exception
Caused by: java.lang.ClassNotFoundException: Didn't find class "com.google.android.gms.iid.InstanceID" on path: DexPathList[[zip file "/data/app/com.ex.test-1/base.apk"],nativeLibraryDirectories=[/data/app/com.ex.test-1/lib/arm, /vendor/lib, /system/lib]]
I have imported the play-services-9.2.0.unitypackage, without any success. Any help?

For anyone who might want to look for this question answered, I found the solution. The InstanceID.class is not included in the play-services-9.2.0.unitypackage, so include the play-services-iid-9.0.2.aar in the Android -> Plugins folder.

java.lang.ClassNotFoundException on startup

We have very weird java.lang.ClassNotFoundException on app startup that happens to very small amount of customers (< 1%). We never saw it in dev env and we cannot understand the source of this issue. Here is the stack trace from Google play crash reports.
java.lang.RuntimeException: Unable to instantiate application com.mycompany.myapplication.MyApplication: java.lang.ClassNotFoundException: com.mycompany.myapplication.MyApplication in loader dalvik.system.PathClassLoader[/mnt/asec/com.mycompany.myapplication-1/pkg.apk]
at android.app.LoadedApk.makeApplication(LoadedApk.java:490)
at android.app.ActivityThread.handleBindApplication(ActivityThread.java:3784)
at android.app.ActivityThread.access$2200(ActivityThread.java:132)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1082)
at android.os.Handler.dispatchMessage(Handler.java:99)
at android.os.Looper.loop(Looper.java:143)
at android.app.ActivityThread.main(ActivityThread.java:4268)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:507)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:839)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:597)
at dalvik.system.NativeStart.main(Native Method)
Caused by: java.lang.ClassNotFoundException: com.mycompany.myapplication.MyApplication in loader dalvik.system.PathClassLoader[/mnt/asec/com.mycompany.myapplication-1/pkg.apk]
at dalvik.system.PathClassLoader.findClass(PathClassLoader.java:240)
at java.lang.ClassLoader.loadClass(ClassLoader.java:551)
at java.lang.ClassLoader.loadClass(ClassLoader.java:511)
at android.app.Instrumentation.newApplication(Instrumentation.java:972)
at android.app.LoadedApk.makeApplication(LoadedApk.java:481)
... 11 more

If the issue only occurs on with signed APKs and you are using Eclipse to Export the Signed APK ...
Before you 'Export and sign an APK' in Eclipse turn off the following setting in the menu [Project > Build Automatically] (then can switch it back on later when you continue developing).

I recently deployed an update to my app, and a user reported a crash the very next day via the Google Play reporting facility. The stack dump was for LoadApk() and the error was in the loading of my Application class. Here is that dump:
java.lang.RuntimeException: Unable to instantiate application com.goalstate.WordGames.FullBoard.library.FullBoardApplication: java.lang.ClassNotFoundException: Didn't find class "com.goalstate.WordGames.FullBoard.library.FullBoardApplication" on path: DexPathList[[],nativeLibraryDirectories=[/vendor/lib, /system/lib]]
at android.app.LoadedApk.makeApplication(LoadedApk.java:516)
at android.app.ActivityThread.handleBindApplication(ActivityThread.java:4703)
at android.app.ActivityThread.access$1600(ActivityThread.java:175)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1368)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:146)
at android.app.ActivityThread.main(ActivityThread.java:5602)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:515)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1283)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1099)
at dalvik.system.NativeStart.main(Native Method)
Caused by: java.lang.ClassNotFoundException: Didn't find class "com.goalstate.WordGames.FullBoard.library.FullBoardApplication" on path: DexPathList[[],nativeLibraryDirectories=[/vendor/lib, /system/lib]]
at dalvik.system.BaseDexClassLoader.findClass(BaseDexClassLoader.java:67)
at java.lang.ClassLoader.loadClass(ClassLoader.java:497)
at java.lang.ClassLoader.loadClass(ClassLoader.java:457)
at android.app.Instrumentation.newApplication(Instrumentation.java:981)
at android.app.LoadedApk.makeApplication(LoadedApk.java:511)
... 11 more
I have a library and my Application class was defined in that library. The manifest for my app (which used the library) referred to the class in that library by its full path. It did not have an application class of its own.
All of my in-house testing had not reproduced this problem, and even when I tested (using the Samsung Remote Test Lab) on the same device (actually two different devices, one running 4.3 and one running 4.4.4) as reported the crash (a Galaxy Note II, running Android 4.4), there was no problem.
In searching for information on this I found mention of the fact that different devices may have slightly different approaches to resolving class references, and that is probably why most devices had no problem with my APK, but this particular device (which, unlike my test devices, was provided with its Android flavor by Sprint) did. And similarly, it may be why just one percent of your own customers had the problem, while most did not.
I decided that the best approach would be to make it as easy as possible for even an unsophisticated device to find the classes that were referenced from my manifest file. So, I defined a new application class within the package of the app itself (rather than the library) and I had that class inherit from the application class in my library. The new class was otherwise empty.
I then replaced the full path reference to the application class in the library with a relative reference to the new class I had created in the app itself. So, instead of having:
<application android:name="com.goalstate.WordGames.FullBoard.library.FullBoardApplication"
in my manifest, I had:
<application android:name=".FullBoardWordChumsApplication"
That (according to folklore on this topic) should make it easier for a less sophisticated resolution process to succeed.
I also took the full path that I had been using in the manifest to name my already-local activity class and made it relative (by simply lopping off everything preceding the final dot).
Additional folklore found online indicates that it may help to turn off "Build Automatically" for the project in Eclipse, then exit Eclipse, re-enter Eclipse, and then, after it rebuilds, go directly to Android Tools to export the signed APK (without ever turning on Build Automatically). So, throwing salt over my left shoulder, and saying a prayer to the gods of fragmentation paranoia, I accommodated this superstition in preparing my APK for release.
Does any of this really help? Time will tell, but so far my updated release has not generated any additional crashes.

This Error occurs when in your manifest file in application tag whatever class name you put it is not match with your coding java file .So make a current both in way.