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Samebug tips

  1. ,
    Expert tip

    Check if you imported android.support.v4.app.FragmentManager and not android.app.FragmentManager. Check for naming problems in your xml files as well, might have inconsistencies!

  2. ,
    Expert tip

    Also, check if you're not using android.support.v4.app.FragmentTransaction with android.app.Fragment, as they're not totally compatible.

Solutions on the web

via Stack Overflow by rising programmer
, 1 year ago
Attempt to write to field 'android.support.v4.app.FragmentManagerImpl android.support.v4.app.Fragment.mFragmentManager' on a null object reference
via Stack Overflow by ALi Akbar
, 1 year ago
Attempt to invoke virtual method 'java.lang.Class java.lang.Object.getClass()' on a null object reference
via GitHub by shaikmdashiq
, 2 years ago
Attempt to write to field 'android.support.v4.app.FragmentManagerImpl android.support.v4.app.Fragment.mFragmentManager' on a null object reference
via Stack Overflow by xyz rety
, 1 year ago
Attempt to invoke virtual method 'java.lang.Class java.lang.Object.getClass()' on a null object reference
via Stack Overflow by Priyansh Bhatt
, 1 year ago
Attempt to invoke virtual method 'java.lang.Class java.lang.Object.getClass()' on a null object reference
via Stack Overflow by Gsingh
, 1 year ago
Attempt to invoke virtual method 'java.lang.Class java.lang.Object.getClass()' on a null object reference
java.lang.NullPointerException: Attempt to write to field 'android.support.v4.app.FragmentManagerImpl android.support.v4.app.Fragment.mFragmentManager' on a null object reference	at android.support.v4.app.BackStackRecord.doAddOp(BackStackRecord.java:414)	at android.support.v4.app.BackStackRecord.add(BackStackRecord.java:409)	at android.support.v4.app.FragmentPagerAdapter.instantiateItem(FragmentPagerAdapter.java:99)	at android.support.v4.view.ViewPager.addNewItem(ViewPager.java:943)	at android.support.v4.view.ViewPager.populate(ViewPager.java:1091)	at android.support.v4.view.ViewPager.populate(ViewPager.java:1025)	at android.support.v4.view.ViewPager.onMeasure(ViewPager.java:1545)	at android.view.View.measure(View.java:18563)	at android.widget.RelativeLayout.measureChildHorizontal(RelativeLayout.java:728)	at android.widget.RelativeLayout.onMeasure(RelativeLayout.java:464)	at android.view.View.measure(View.java:18563)	at android.widget.RelativeLayout.measureChildHorizontal(RelativeLayout.java:728)	at android.widget.RelativeLayout.onMeasure(RelativeLayout.java:464)	at android.view.View.measure(View.java:18563)	at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5827)	at android.widget.FrameLayout.onMeasure(FrameLayout.java:430)	at android.support.v7.widget.ContentFrameLayout.onMeasure(ContentFrameLayout.java:135)	at android.view.View.measure(View.java:18563)	at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5827)	at android.widget.LinearLayout.measureChildBeforeLayout(LinearLayout.java:1435)	at android.widget.LinearLayout.measureVertical(LinearLayout.java:721)	at android.widget.LinearLayout.onMeasure(LinearLayout.java:612)	at android.view.View.measure(View.java:18563)	at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5827)	at android.widget.FrameLayout.onMeasure(FrameLayout.java:430)	at android.view.View.measure(View.java:18563)	at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5827)	at android.widget.LinearLayout.measureChildBeforeLayout(LinearLayout.java:1435)	at android.widget.LinearLayout.measureVertical(LinearLayout.java:721)	at android.widget.LinearLayout.onMeasure(LinearLayout.java:612)	at android.view.View.measure(View.java:18563)	at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5827)	at android.widget.FrameLayout.onMeasure(FrameLayout.java:430)	at com.android.internal.policy.impl.PhoneWindow$DecorView.onMeasure(PhoneWindow.java:2888)	at android.view.View.measure(View.java:18563)	at android.view.ViewRootImpl.performMeasure(ViewRootImpl.java:2248)	at android.view.ViewRootImpl.measureHierarchy(ViewRootImpl.java:1306)	at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:1548)	at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:1191)	at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:6642)	at android.view.Choreographer$CallbackRecord.run(Choreographer.java:777)	at android.view.Choreographer.doCallbacks(Choreographer.java:590)	at android.view.Choreographer.doFrame(Choreographer.java:560)	at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:763)	at android.os.Handler.handleCallback(Handler.java:739)	at android.os.Handler.dispatchMessage(Handler.java:95)	at android.os.Looper.loop(Looper.java:145)	at android.app.ActivityThread.main(ActivityThread.java:5938)	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:1400)	at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1195)