Unfortunately MyApp has stopped How can I solve this

Question

I am developing an application  and everytime I run it  I get the message      Unfortunately  MyApp has stopped    What can I do to solve this     About this question - obviously inspired by What is a stack trace  and how can I use it to debug my application errors   there are lots of questions stating that their application has crashed  without any further detail  This question aims to instruct novice Android programmers on how to try and fix their problems themselves  or ask the right questions

User · Answer

This popup shows only when you get a fatal exception in your code which stops the execution of the app. It could be any exception NullPointerException, OutOfMemoryException etc.

Best way to check is through Logcat if you are still developing the app in Android studio which is quick way to read stack trace and check the cause of the app.

If your app is already live, then you can not use logcat. So, for that you can implement Crashlytics to provide you bug reports of any exception that occurs.

User · Answer

If your app for some reason crashes without good stacktrace  Try debug it from first line  and go line by line until crash  Then you will have answer  which line is causing you trouble  Proably you could then wrapp it into try catch block and print error output

User · Answer

Crash during development  Try my favourite tool logview to get the logs and analyze them during development  Make sure to mark   logview and   lib logview jar as executable when running in Linux   If you don t like it  there re a lot of alternative desktop log viewers for Android   Crash in the wild  Integrate a real-time crash reporting tool such as Firebase Crashlytics in order to get stacktraces of unhandled exceptions which occurred on users  devices   Read How to Release a Buggy App  And Live to Tell the Tale  to know more about handling bugs in the field

User · Answer

You can use any of these tools    adb logcat  adb logcat  gt  logs txt  you can use editors to open and search errors    eclipse logcat  If not visible in eclipse  Go to Windows- gt Show View- gt Others- gt Android- gt LogCat   Android Debug Monitor or Android Device Monitor type command monitor or open through UI        Android Studio   I suggest to use Android Debug Monitor  it is good  Because eclipse hangs when too many logs are there  and through adb logcat filter and all difficult

User · Answer

People make mistakes  and so coding as well    When ever any error happened  always check with the logcat with the text in red color however u can find out the real problem in blue color text with underline in those red color text    Make sure if u create a new activity  always declare the activity in the AndroidManifest file   If adding Permission  declare it in the AndroidMainifest file as well

User · Answer

Note  This answer is using Android Studio 2 2 2  Note 2  I am considering that your device is successfully connected      The first thing you do when your application crashes is look into the LogCat  at the bottom of Android Studio there s a toolbar with a list of menus     Click on the  Android Monitor   The one I underlined in the image above      Now  you ll get something like this     Change  Verbose  to  Error  Now it will only show you logged errors  Don t worry about all these errors  if you got them  now     Ok  Now  do what you did to crash your app  After your app crashes  go to your logcat  You should find a new crash log that has a lot of at x x x  and Caused by  TrumpIsPresidentException for example  Go to that Caused by  statement in your logcat     Next to that Caused By   there should be the Exception that happened  In my case  it s a RuntimeException and under it there should be a line which contains a blue link such as     If that Caused by  DOESN T have a line with a blue text somewhere under it  then look for another Caused by  that does   Click on that blue link  It should take you to where the problem occured  In my case  it was due to this line   throw new RuntimeException      So  now I know why it s crashing  It s because I m throwing the exception myself  This was an obvious error     However  let s say I got another error   java lang NullPointerException   I checked my logcat  I clicked on the blue link it gave me  and it took me here   mTextView setText myString     So  now I want to debug  According to this StackOverflow question  a NullPointerException says that something is null   So  let s find out what is null  There s two possibilities  Either mTextView is null  or myString is null  To find out  before the mTextView setText mString  line  I add these two lines   Log d  AppDebug   mTextView is null      String valueOf mTextView    null   Log d  AppDebug   myString is null      String valueOf myString   null     Now  like we did previously  We changed Verose to Error   we want to change  Error  to  Debug   Since we re logging by debugging  Here s all the Log methods   Log    d means Debug   e means error   w means warning   v means verbose   i means information   wtf means  What a terrible failure   This is similar to Log e   So  since we used Log d  we re checking in Debug  That s why we changed it to debug   Notice Log d has a first parameter in our case  AppDebug   Click on the  No Filters  drop down menu on the top-right of the logcat  Select  Edit Filter Configuration   give a name to your filter  and in  Log Tag  put  App Debug   Click  OK   Now  you should see two lines in the logcat   yourPackageNameAndApp  mTextView is null  true yourPackageNameAndApp  myString is null  false   So now we know that mTextView is null    I observe my code  now I notice something   I have private TextView mTextView declared at the top of my class  But  I m not defining it   Basically I forgot to do this in my onCreate     mTextView    TextView  findViewById R id textview id in xml     So THAT S why mTextView is null  because I forgot to tell my app what it is  So I add that line  run my app  and now the app doesn t crash

User · Answer

Logcat - To check the logs in the development phase of Android Studio  Initially clear the Logcat and let the app crash again so you can get only crashed log detail  You have to check the Stack trace     While  Unfortunately  MyApp has stopped  There are many reasons for it  You can check same in logs  For this  you can use the Log e  TAG   Message      Common error during app crash like    Coding mistake Wrong use of keywords   Mismatch property name  Unsupported plugin maybe   Mismatch version maybe   Activity missing in AndroidManifest file  Permission missing in AndroidManifest file  Most common NullPointerException  Declared but not defined    To resolve app crash error    Keep in mind above points and go through it  With the error  you will get the file name also in blue colour  click on them and jump to code from error is occurring

User · Answer

Let me share a basic Logcat analysis for when you meet a Force Close  when the app stops working    DOCS  The basic tool from Android to collect analyze logs is the logcat    HERE is the Android s page about logcat  If you use android Studio  you can also check this LINK   Capturing  Basically  you can MANUALLY capture logcat with the following command  or just check AndroidMonitor window in AndroidStudio    adb logcat   There s a lot of parameters you can add to the command which helps you to filter and display the message that you want    This is personal     I always use the command below to get the message timestamp   adb logcat -v time   You can redirect the output to a file and analyze it in a Text Editor   Analyzing  If you app is Crashing  you ll get something like   07-09 08 29 13 474 21144-21144 com example khan abc D AndroidRuntime  Shutting down VM 07-09 08 29 13 475 21144-21144 com example khan abc E AndroidRuntime  FATAL EXCEPTION  main     Process  com example khan abc  PID  21144     java lang NullPointerException  Attempt to invoke virtual method  void android support v4 app FragmentActivity onBackPressed    on a null object reference      at com example khan abc AudioFragment 1 onClick AudioFragment java 125       at android view View performClick View java 4848       at android view View PerformClick run View java 20262       at android os Handler handleCallback Handler java 815       at android os Handler dispatchMessage Handler java 104       at android os Looper loop Looper java 194       at android app ActivityThread main ActivityThread java 5631       at java lang reflect Method invoke Native Method       at java lang reflect Method invoke Method java 372       at com android internal os ZygoteInit MethodAndArgsCaller run ZygoteInit java 959       at com android internal os ZygoteInit main ZygoteInit java 754  07-09 08 29 15 195 21144-21144 com example khan abc I Process  Sending signal  PID  21144 SIG  9   This part of the log shows you a lot of information    When the issue happened  07-09 08 29 13 475   It is important to check when the issue happened    You may find several errors in a log    you must be sure that you are checking the proper messages      Which app crashed  com example khan abc   This way  you know which app crashed  to be sure that you are checking the logs about your message    Which ERROR  java lang NullPointerException   A NULL Pointer Exception error   Detailed info about the error  Attempt to invoke virtual method  void android support v4 app FragmentActivity onBackPressed    on a null object reference   You tried to call method onBackPressed   from a FragmentActivity object  However  that object was null when you did it    Stack Trace  Stack Trace shows you the method invocation order    Sometimes  the error happens in the calling method  and not in the called method    at com example khan abc AudioFragment 1 onClick AudioFragment java 125    Error happened in file com example khan abc AudioFragment java  inside onClick   method at line  125  stacktrace shows the line that error happened   It was called by   at android view View performClick View java 4848    Which was called by   at android view View PerformClick run View java 20262    which was called by   at android os Handler handleCallback Handler java 815    etc      Overview  This was just an overview    Not all logs are simple but the error gives specific problem and verbose shows up all problem     It is just to share the idea and provide entry-level information to you      I hope I could help you someway    Regards

User · Answer

If you don t have any kind of interesting log in your terminal  or they are not directly related to your app   maybe your problem is due to a native library  In that case  you should check for the  tombstone  files within your terminal    The default location for the tombstone files depends on every device  but if that s the case  you will have a log telling  Tombstone written to   data tombstones tombstone 06  For more information  check on https   source android com devices tech debug

User · Answer

This answer describes the process of retrieving the stack trace  Already have the stack trace  Read up on stack traces in  What is a stack trace  and how can I use it to debug my application errors    The Problem  Your application quit because an uncaught RuntimeException was thrown  The most common of these is the NullPointerException   How to solve it   Every time an Android application crashes  or any Java application for that matter   a Stack trace is written to the console  in this case  logcat   This stack trace contains vital information for solving your problem   Android Studio    In the bottom bar of the window  click on the Logcat button  Alternatively  you can press alt 6  Make sure your emulator or device is selected in the Devices panel  Next  try to find the stack trace  which is shown in red  There may be a lot of stuff logged into logcat  so you may need to scroll a bit  An easy way to find the stack trace is to clear the logcat  using the recycle bin on the right   and let the app crash again   I have found the stack trace  now what   Yay  You re halfway to solving your problem  You only need to find out what exactly made your application crash  by analyzing the stack trace   Read up on stack traces in  What is a stack trace  and how can I use it to debug my application errors    I still can t solve my problem   If you ve found your Exception and the line where it occurred  and still cannot figure out how to fix it  don t hesitate to ask a question on StackOverflow     Try to be as concise as possible  post the stack trace  and the relevant code  e g  a few lines up to the line which threw the Exception

User · Answer

Check your Logcat message and see your Manifest file  There should be something missing like defining the Activity User permission   etc

User · Answer

In below showToast   method you have to pass another parameter for context or application context by doing so you can try it     public void showToast String error  Context applicationContext           LayoutInflater inflater   getLayoutInflater            View view   inflater inflate R layout custom toast   ViewGroup                findViewById R id toast root            TextView text    TextView  findViewById R id toast error           text setText error           Toast toast   new Toast applicationContext           toast setGravity Gravity TOP   Gravity FILL HORIZONTAL  0  0           toast setDuration Toast LENGTH SHORT           toast setView view           toast show

User · Answer

First  you check which point your app has crashed  Unfortunately  MyApp has stopped    For this  you can use Log e  TAG    Message     using this line you can see your app log in logcat   After that  you find which point your app has stopped it s very easy to solve at your side

User · Answer

You have to check the Stack trace  How to do that   on Your IDE Check the windows form LOGCAT   If you cant see the logcat windows go to this path and open it   window- gt show view- gt others- gt Android- gt Logcat   if you are using Google-Api go to this path   adb logcat   logcat txt

User · Answer

Use the LogCat and try to find what is causing the app to crash   To see Logcat if you use Android Studio then Press ALT   6 or  if you use Eclipse then  Window -  Open Perspective -  Other - LogCat   Go to the LogCat  from the drop down menu select error  This will contain all the required information to help you debug  If that doesn t help  post the LogCat as an edit to your question and somebody will help you out

User · Answer

Also running this command in terminal can help find the problem  gradlew build  gt  log txt 2 gt details txt  then you should go to gradlew file location in read two above log files

User · Answer

You can use Google s ADB tool to get Logcat file to analyze the issue   adb logcat  gt  logcat txt   open logcat txt file and search for your application name  There should be information on why it failed  the line number  Class name  etc

User · Answer

Just check the error in log cat    You get the log cat option from in eclipse      window- show view- others- Android- Logcat   Log cat contains error   Other wise you can also check the error by executing an application in debug mode  Firstly set breakpoint after that by doing      right click on project- debug as- Android application

User · Answer

First  you need to check where and why your app has been crashed  Unfortunately  MyApp has stopped    With the help of LOG  you can figure it out what went wrong   After that  you find which point your app has stopped fix that from your point

User · Answer

You can also get this error message on its own  without any stack trace or any further error message   In this case you need to make sure your Android manifest is configured correctly  including any manifest merging happening from a library and any activity that would come from a library   and pay particular attention to the first activity displayed in your application in your manifest files

[java] Unfortunately MyApp has stopped. How can I solve this?

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