Android. Events. App crashes if restore it from background

[danylopidhainyi23]

Devices:

• Samsung Galaxy S4, OS 5.0.1
• Samsung Galaxy S3, OS 4.3
• Nexus 5, OS 6.0.1
• Nexus 5X, OS 7.0

Precondition: 'Don't keep activities' is active

STR:

1. Launch app
2. Open Events screen (sessions, bofs, social events)
3. Hide app to background
4. Restore it

Actual: Crash

Crash logs attached:

Nexus 5X, OS 7.0:
12-01 17:24:01.461: E/AndroidRuntime(23378): FATAL EXCEPTION: main
12-01 17:24:01.461: E/AndroidRuntime(23378): Process: com.ls.drupalconapp, PID: 23378
12-01 17:24:01.461: E/AndroidRuntime(23378): java.lang.NullPointerException: Attempt to invoke virtual method 'android.content.SharedPreferences android.content.Context.getSharedPreferences(java.lang.String, int)' on a null object reference
12-01 17:24:01.461: E/AndroidRuntime(23378): at com.connfa.model.PreferencesManager.(PreferencesManager.java:29)
12-01 17:24:01.461: E/AndroidRuntime(23378): at com.connfa.model.PreferencesManager.create(PreferencesManager.java:23)
12-01 17:24:01.461: E/AndroidRuntime(23378): at com.connfa.utils.DateUtils.getTimeZone(DateUtils.java:18)
12-01 17:24:01.461: E/AndroidRuntime(23378): at com.connfa.utils.DateUtils.isToday(DateUtils.java:38)
12-01 17:24:01.461: E/AndroidRuntime(23378): at com.connfa.ui.fragment.EventHolderFragment.switchToCurrentDay(EventHolderFragment.java:272)
12-01 17:24:01.461: E/AndroidRuntime(23378): at com.connfa.ui.fragment.EventHolderFragment.updateViews(EventHolderFragment.java:266)
12-01 17:24:01.461: E/AndroidRuntime(23378): at com.connfa.ui.fragment.EventHolderFragment.access$300(EventHolderFragment.java:38)
12-01 17:24:01.461: E/AndroidRuntime(23378): at com.connfa.ui.fragment.EventHolderFragment$LoadData.onPostExecute(EventHolderFragment.java:193)
12-01 17:24:01.461: E/AndroidRuntime(23378): at com.connfa.ui.fragment.EventHolderFragment$LoadData.onPostExecute(EventHolderFragment.java:184)
12-01 17:24:01.461: E/AndroidRuntime(23378): at android.os.AsyncTask.finish(AsyncTask.java:660)
12-01 17:24:01.461: E/AndroidRuntime(23378): at android.os.AsyncTask.-wrap1(AsyncTask.java)
12-01 17:24:01.461: E/AndroidRuntime(23378): at android.os.AsyncTask$InternalHandler.handleMessage(AsyncTask.java:677)
12-01 17:24:01.461: E/AndroidRuntime(23378): at android.os.Handler.dispatchMessage(Handler.java:102)
12-01 17:24:01.461: E/AndroidRuntime(23378): at android.os.Looper.loop(Looper.java:154)
12-01 17:24:01.461: E/AndroidRuntime(23378): at android.app.ActivityThread.main(ActivityThread.java:6077)
12-01 17:24:01.461: E/AndroidRuntime(23378): at java.lang.reflect.Method.invoke(Native Method)
12-01 17:24:01.461: E/AndroidRuntime(23378): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:865)
12-01 17:24:01.461: E/AndroidRuntime(23378): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:755)

Samsung Galaxy S3, OS 4.3:
12-01 17:27:33.655: E/AndroidRuntime(25472): FATAL EXCEPTION: main
12-01 17:27:33.655: E/AndroidRuntime(25472): java.lang.NullPointerException
12-01 17:27:33.655: E/AndroidRuntime(25472): at com.connfa.model.PreferencesManager.(PreferencesManager.java:29)
12-01 17:27:33.655: E/AndroidRuntime(25472): at com.connfa.model.PreferencesManager.create(PreferencesManager.java:23)
12-01 17:27:33.655: E/AndroidRuntime(25472): at com.connfa.utils.DateUtils.getTimeZone(DateUtils.java:18)
12-01 17:27:33.655: E/AndroidRuntime(25472): at com.connfa.utils.DateUtils.isToday(DateUtils.java:38)
12-01 17:27:33.655: E/AndroidRuntime(25472): at com.connfa.ui.fragment.EventHolderFragment.switchToCurrentDay(EventHolderFragment.java:272)
12-01 17:27:33.655: E/AndroidRuntime(25472): at com.connfa.ui.fragment.EventHolderFragment.updateViews(EventHolderFragment.java:266)
12-01 17:27:33.655: E/AndroidRuntime(25472): at com.connfa.ui.fragment.EventHolderFragment.access$300(EventHolderFragment.java:38)
12-01 17:27:33.655: E/AndroidRuntime(25472): at com.connfa.ui.fragment.EventHolderFragment$LoadData.onPostExecute(EventHolderFragment.java:193)
12-01 17:27:33.655: E/AndroidRuntime(25472): at com.connfa.ui.fragment.EventHolderFragment$LoadData.onPostExecute(EventHolderFragment.java:184)
12-01 17:27:33.655: E/AndroidRuntime(25472): at android.os.AsyncTask.finish(AsyncTask.java:631)
12-01 17:27:33.655: E/AndroidRuntime(25472): at android.os.AsyncTask.access$600(AsyncTask.java:177)
12-01 17:27:33.655: E/AndroidRuntime(25472): at android.os.AsyncTask$InternalHandler.handleMessage(AsyncTask.java:644)
12-01 17:27:33.655: E/AndroidRuntime(25472): at android.os.Handler.dispatchMessage(Handler.java:99)
12-01 17:27:33.655: E/AndroidRuntime(25472): at android.os.Looper.loop(Looper.java:176)
12-01 17:27:33.655: E/AndroidRuntime(25472): at android.app.ActivityThread.main(ActivityThread.java:5419)
12-01 17:27:33.655: E/AndroidRuntime(25472): at java.lang.reflect.Method.invokeNative(Native Method)
12-01 17:27:33.655: E/AndroidRuntime(25472): at java.lang.reflect.Method.invoke(Method.java:525)
12-01 17:27:33.655: E/AndroidRuntime(25472): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1046)
12-01 17:27:33.655: E/AndroidRuntime(25472): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:862)
12-01 17:27:33.655: E/AndroidRuntime(25472): at dalvik.system.NativeStart.main(Native Method)