title: suddenly my android application crashes
body: <p>Sorry guys for the newbie questions. I'm new to android, was working to set some login system in new application. Everything worked fine (after a long while), i had a login button from the menu in the main page which was just an empty "hello world" default activity. Then I decided to remove the "hello world" text view, i tried to run it immediately and the application crashed with null exception. I was doing ctrl+z like crazy but the application keeps on crashing. 
  i understand absolutely nothing from the LogCat:</p>
  
  <blockquote>
    <p>10-24 00:10:17.982: I/ActivityManager(59): Starting activity: Intent {
    act=android.intent.action.MAIN cat=[android.intent.category.LAUNCHER]
    flg=0x10200000
    cmp=com.application.mySoSpecialApplication/.MainActivity } 10-24
    00:10:18.002: W/WindowManager(59): HistoryRecord{4505f618
    com.application.mySoSpecialApplication/.MainActivity} failed creating
    starting window 10-24 00:10:18.002: W/WindowManager(59):
    java.lang.RuntimeException: Binary XML file line #25: You must supply
    a layout_height attribute. 10-24 00:10:18.002: W/WindowManager(59):
      at
    android.content.res.TypedArray.getLayoutDimension(TypedArray.java:491)
    10-24 00:10:18.002: W/WindowManager(59):  at
    android.view.ViewGroup$LayoutParams.setBaseAttributes(ViewGroup.java:3593)
    10-24 00:10:18.002: W/WindowManager(59):  at
    android.view.ViewGroup$MarginLayoutParams.(ViewGroup.java:3672)
    10-24 00:10:18.002: W/WindowManager(59):  at
    android.widget.LinearLayout$LayoutParams.(LinearLayout.java:1395)
    10-24 00:10:18.002: W/WindowManager(59):  at
    android.widget.LinearLayout.generateLayoutParams(LinearLayout.java:1321)
    10-24 00:10:18.002: W/WindowManager(59):  at
    android.widget.LinearLayout.generateLayoutParams(LinearLayout.java:45)
    10-24 00:10:18.002: W/WindowManager(59):  at
    android.view.LayoutInflater.rInflate(LayoutInflater.java:620) 10-24
    00:10:18.002: W/WindowManager(59):    at
    android.view.LayoutInflater.inflate(LayoutInflater.java:407) 10-24
    00:10:18.002: W/WindowManager(59):    at
    android.view.LayoutInflater.inflate(LayoutInflater.java:320) 10-24
    00:10:18.002: W/WindowManager(59):    at
    android.view.LayoutInflater.inflate(LayoutInflater.java:276) 10-24
    00:10:18.002: W/WindowManager(59):    at
    com.android.internal.policy.impl.PhoneWindow.generateLayout(PhoneWindow.java:2165)
    10-24 00:10:18.002: W/WindowManager(59):  at
    com.android.internal.policy.impl.PhoneWindow.installDecor(PhoneWindow.java:2220)
    10-24 00:10:18.002: W/WindowManager(59):  at
    com.android.internal.policy.impl.PhoneWindow.getDecorView(PhoneWindow.java:1407)
    10-24 00:10:18.002: W/WindowManager(59):  at
    com.android.internal.policy.impl.PhoneWindowManager.addStartingWindow(PhoneWindowManager.java:894)
    10-24 00:10:18.002: W/WindowManager(59):  at
    com.android.server.WindowManagerService$H.handleMessage(WindowManagerService.java:9007)
    10-24 00:10:18.002: W/WindowManager(59):  at
    android.os.Handler.dispatchMessage(Handler.java:99) 10-24
    00:10:18.002: W/WindowManager(59):    at
    android.os.Looper.loop(Looper.java:123) 10-24 00:10:18.002:
    W/WindowManager(59):  at
    com.android.server.WindowManagerService$WMThread.run(WindowManagerService.java:570)
    10-24 00:10:18.042: I/ActivityManager(59): Start proc
    com.application.mySoSpecialApplication for activity
    com.application.mySoSpecialApplication/.MainActivity: pid=463
    uid=10036 gids={3003} 10-24 00:10:18.272: D/AndroidRuntime(463):
    Shutting down VM 10-24 00:10:18.272: W/dalvikvm(463): threadid=1:
    thread exiting with uncaught exception (group=0x4001d800) 10-24
    00:10:18.292: E/AndroidRuntime(463): FATAL EXCEPTION: main 10-24
    00:10:18.292: E/AndroidRuntime(463): java.lang.RuntimeException:
    Unable to instantiate application
    com.application.mySoSpecialApplication.mySoSpecialApplicationApplication:
    java.lang.NullPointerException 10-24 00:10:18.292:
    E/AndroidRuntime(463):    at
    android.app.ActivityThread$PackageInfo.makeApplication(ActivityThread.java:649)
    10-24 00:10:18.292: E/AndroidRuntime(463):    at
    android.app.ActivityThread.handleBindApplication(ActivityThread.java:4232)
    10-24 00:10:18.292: E/AndroidRuntime(463):    at
    android.app.ActivityThread.access$3000(ActivityThread.java:125) 10-24
    00:10:18.292: E/AndroidRuntime(463):  at
    android.app.ActivityThread$H.handleMessage(ActivityThread.java:2071)
    10-24 00:10:18.292: E/AndroidRuntime(463):    at
    android.os.Handler.dispatchMessage(Handler.java:99) 10-24
    00:10:18.292: E/AndroidRuntime(463):  at
    android.os.Looper.loop(Looper.java:123) 10-24 00:10:18.292:
    E/AndroidRuntime(463):    at
    android.app.ActivityThread.main(ActivityThread.java:4627) 10-24
    00:10:18.292: E/AndroidRuntime(463):  at
    java.lang.reflect.Method.invokeNative(Native Method) 10-24
    00:10:18.292: E/AndroidRuntime(463):  at
    java.lang.reflect.Method.invoke(Method.java:521) 10-24 00:10:18.292:
    E/AndroidRuntime(463):    at
    com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:868)
    10-24 00:10:18.292: E/AndroidRuntime(463):    at
    com.android.internal.os.ZygoteInit.main(ZygoteInit.java:626) 10-24
    00:10:18.292: E/AndroidRuntime(463):  at
    dalvik.system.NativeStart.main(Native Method) 10-24 00:10:18.292:
    E/AndroidRuntime(463): Caused by: java.lang.NullPointerException 10-24
    00:10:18.292: E/AndroidRuntime(463):  at
    android.content.ContextWrapper.getContentResolver(ContextWrapper.java:90)
    10-24 00:10:18.292: E/AndroidRuntime(463):    at
    com.application.mySoSpecialApplication.mySoSpecialApplicationApplication.(mySoSpecialApplicationApplication.java:14)
    10-24 00:10:18.292: E/AndroidRuntime(463):    at
    java.lang.Class.newInstanceImpl(Native Method) 10-24 00:10:18.292:
    E/AndroidRuntime(463):    at
    java.lang.Class.newInstance(Class.java:1429) 10-24 00:10:18.292:
    E/AndroidRuntime(463):    at
    android.app.Instrumentation.newApplication(Instrumentation.java:957)
    10-24 00:10:18.292: E/AndroidRuntime(463):    at
    android.app.Instrumentation.newApplication(Instrumentation.java:942)
    10-24 00:10:18.292: E/AndroidRuntime(463):    at
    android.app.ActivityThread$PackageInfo.makeApplication(ActivityThread.java:644)
    10-24 00:10:18.292: E/AndroidRuntime(463):    ... 11 more 10-24
    00:10:18.312: W/ActivityManager(59):   Force finishing activity
    com.application.mySoSpecialApplication/.MainActivity 10-24
    00:10:18.968: W/ActivityManager(59): Activity pause timeout for
    HistoryRecord{4505f618
    com.application.mySoSpecialApplication/.MainActivity} 10-24
    00:10:21.322: I/Process(463): Sending signal. PID: 463 SIG: 9 10-24
    00:10:21.352: I/ActivityManager(59): Process
    com.application.mySoSpecialApplication (pid 463) has died. 10-24
    00:10:21.383: W/InputManagerService(59): Window already focused,
    ignoring focus gain of:
    com.android.internal.view.IInputMethodClient$Stub$Proxy@44fc1780 10-24
    00:10:29.087: W/ActivityManager(59): Activity destroy timeout for
    HistoryRecord{4505f618
    com.application.mySoSpecialApplication/.MainActivity}</p>
  </blockquote>
  
  <p>Maybe one of you guys will figure out where is the problem. Thank you very much. </p>