java.lang.NullPointerException

Attempt to write to field 'android.support.v4.app.FragmentManagerImpl android.support.v4.app.Fragment.mFragmentManager' on a null object reference

Samebug tips2

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!


rafaelrafael

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


rafaelrafael

Don't give up yet. Our experts can help. Paste your full stack trace to get a solution.

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  • Stack trace

    • 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:418) at android.support.v4.app.BackStackRecord.replace(BackStackRecord.java:453) at android.support.v4.app.BackStackRecord.replace(BackStackRecord.java:445) at application.cedie.myapplication.MainActivity.onNavigationItemSelected(MainActivity.java:128) at android.support.design.widget.NavigationView$1.onMenuItemSelected(NavigationView.java:151) at android.support.v7.view.menu.MenuBuilder.dispatchMenuItemSelected(MenuBuilder.java:811) at android.support.v7.view.menu.MenuItemImpl.invoke(MenuItemImpl.java:152) at android.support.v7.view.menu.MenuBuilder.performItemAction(MenuBuilder.java:958) at android.support.design.internal.NavigationMenuPresenter$1.onClick(NavigationMenuPresenter.java:318) at android.view.View.performClick(View.java:4756) at android.view.View$PerformClick.run(View.java:19761) at android.os.Handler.handleCallback(Handler.java:739) at android.os.Handler.dispatchMessage(Handler.java:95) at android.os.Looper.loop(Looper.java:135) at android.app.ActivityThread.main(ActivityThread.java:5253) 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:949) at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:744)

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