这似乎是一个特殊情况，现在似乎只出现在运行API 23的Nexus 6上，而不是仿真器或（一对）4.4设备上。我使用我的应用程序类作为Singleton，通常它不会导致任何问题。但不知何故，在Nexus上，它会在应用程序类的任何引用上崩溃，因为它总是返回null。之后，应用程序运行正常，因此这仅在初始安装后（当应用程序被删除或之前未安装时）发生。
public class MyApp extends Application {
private static MyApp APP_INSTANCE;
public static MyApp getInstance() { return APP_INSTANCE; }
@Override
public void onCreate() {
super.onCreate();
APP_INSTANCE = this;
// rest of code
}
}
因此，无论是MyApp.getInstance()中的MainActivity，还是MainFragment，onCreate或onStart中的onResume，都会崩溃甚至在应用程序运行之后。
调试时不会发生问题。似乎活动正在减慢，因此有时间创建应用程序类的实例，但是当我跳过所有初始调用以获取MainActivity中的实例然后尝试稍后获取它（之后）登录我的MainFragment仍然是null。
此外，我尝试记录整个过程，我看到应用程序类的初始化已完成，因为我的HttpClients已设置并正常工作，但onCreate未被调用。
所以......任何人都知道造成这种情况的原因是什么？
添加了初始安装和第二次启动的StackTrace
初始安装
09-07 12:46:43.240 2741-2741/com.myapp.d I/Process﹕ Sending signal. PID: 2741 SIG: 9
09-07 12:50:55.150 7068-7068/com.myapp.d W/System﹕ ClassLoader referenced unknown path: /data/app/com.myapp.d-1/lib/arm
09-07 12:50:56.346 7068-7068/com.myapp.d W/ClientFactory﹕ Returning UNSAFE client
09-07 12:50:56.360 7068-7068/com.myapp.d I/ClientFactory﹕ Supported CipherSuites: [...ciphersuits here...]
09-07 12:50:56.362 7068-7068/com.myapp.d I/MyApp﹕ Returning App Instance
09-07 12:50:56.362 7068-7068/com.myapp.d I/MainActivity﹕ Init UI
09-07 12:50:56.389 7068-7068/com.myapp.d I/AppCompatViewInflater﹕ app:theme is now deprecated. Please move to using android:theme instead.
09-07 12:50:56.446 7068-7068/com.myapp.d I/MyApp﹕ Returning App Instance
09-07 12:50:56.512 7068-7068/com.myapp.d I/MainActivity﹕ Check Startup
09-07 12:50:56.512 7068-7068/com.myapp.d E/MainActivity﹕ initApp(): start
09-07 12:50:56.512 7068-7068/com.myapp.d D/AndroidRuntime﹕ Shutting down VM
09-07 12:50:56.513 7068-7068/com.myapp.d E/AndroidRuntime﹕ FATAL EXCEPTION: main
Process: com.myapp.d, PID: 7068
java.lang.RuntimeException: Unable to start activity ComponentInfo{com.myapp.d/com.myapp.ui.MainActivity}: java.lang.NullPointerException: Attempt to invoke virtual method 'boolean com.myapp.MyApp.isFirstBoot()' on a null object reference
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2416)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2476)
at android.app.ActivityThread.-wrap11(ActivityThread.java)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1344)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:148)
at android.app.ActivityThread.main(ActivityThread.java:5417)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)
Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'boolean com.myapp.MyApp.isFirstBoot()' on a null object reference
at com.myapp.ui.MainActivity.initApp(MainActivity.java:173)
at com.myapp.ui.MainActivity.onCreate(MainActivity.java:116)
at android.app.Activity.performCreate(Activity.java:6237)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1107)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2369)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2476)
at android.app.ActivityThread.-wrap11(ActivityThread.java)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1344)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:148)
at android.app.ActivityThread.main(ActivityThread.java:5417)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)
第二次启动
09-07 12:54:07.970 7068-7068/com.myapp.d I/Process﹕ Sending signal. PID: 7068 SIG: 9
09-07 12:54:10.386 8420-8420/com.myapp.d W/System﹕ ClassLoader referenced unknown path: /data/app/com.myapp.d-1/lib/arm
09-07 12:54:10.397 8420-8420/com.myapp.d W/ClientFactory﹕ Returning UNSAFE client
09-07 12:54:10.409 8420-8420/com.myapp.d I/ClientFactory﹕ Supported CipherSuites: [...ciphersuites here...]
09-07 12:54:10.410 8420-8420/com.myapp.d I/MyApp﹕ onCreate()
09-07 12:54:10.766 8420-8420/com.myapp.d I/CrashlyticsCore﹕ Initializing Crashlytics 2.3.4.74
09-07 12:54:10.811 8420-8420/com.myapp.d I/MyApp﹕ Returning App Instance
09-07 12:54:10.811 8420-8420/com.myapp.d I/MainActivity﹕ Init UI
09-07 12:54:10.833 8420-8420/com.myapp.d I/AppCompatViewInflater﹕ app:theme is now deprecated. Please move to using android:theme instead.
09-07 12:54:10.883 8420-8426/com.myapp.d W/art﹕ Suspending all threads took: 5.763ms
09-07 12:54:10.887 8420-8420/com.myapp.d I/MyApp﹕ Returning App Instance
09-07 12:54:10.953 8420-8420/com.myapp.d I/MainActivity﹕ Check Startup
09-07 12:54:10.953 8420-8420/com.myapp.d E/MainActivity﹕ initApp(): start
09-07 12:54:10.954 8420-8420/com.myapp.d I/MyApp﹕ Check for first boot: false
09-07 12:54:10.954 8420-8420/com.myapp.d I/MyApp﹕ Check for updated app: false
09-07 12:54:10.959 8420-8420/com.myapp.d D//SpiceManager.java:489﹕ 12:54:10.959 main adding request to request queue
09-07 12:54:10.959 8420-8420/com.myapp.d E/MainActivity﹕ initApp(): autoLogin
09-07 12:54:10.960 8420-8420/com.myapp.d E/MainActivity﹕ initApp(): end
和Manifest文件一样，没什么特别的，但以防万一
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.myapp">
<!-- all my permissions: nothing special -->
<application
android:name="com.myapp.MyApp"
android:allowBackup="true"
android:icon="@mipmap/ic_launcher"
android:label="@string/app.label"
android:theme="@style/AppTheme">
<activity
android:name=".ui.MainActivity"
android:configChanges="orientation"
android:screenOrientation="portrait">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<!-- Other activities and services below -->
<!-- And API KEYS go here -->
</application>
</manifest>