Tengo un Fragmento de inicio de sesión que intenta acceder(TelephonyManager) getActivity().getSystemService(Context.TELEPHONY_SERVICE); esto funciona bien con dispositivos hasta Lollipop 5.1. Y cuando lo probé en Marshmallow 6.01 mostró una excepción de seguridad. Así que agregué código de documentos de Android para solicitar permiso en tiempo de ejecución. Aqui esta el codigo

int permissionCheck = ContextCompat.checkSelfPermission(getActivity(),Manifest.permission.READ_SMS);
    if (permissionCheck != PackageManager.PERMISSION_GRANTED) {

        // Should we show an explanation?
        if (ActivityCompat.shouldShowRequestPermissionRationale(getActivity(), Manifest.permission.READ_SMS)) {

            // Show an expanation to the user *asynchronously* -- don't block
            // this thread waiting for the user's response! After the user
            // sees the explanation, try again to request the permission.



        } else {

            // No explanation needed, we can request the permission.

            ActivityCompat.requestPermissions(getActivity(),new String[]{Manifest.permission.READ_SMS},REQUEST_SMS);

            // REQUEST_SMS is an
            // app-defined int constant. The callback method gets the
            // result of the request.
        }
    }else {
        tMgr = (TelephonyManager) getActivity().getSystemService(Context.TELEPHONY_SERVICE);

    }

Ahora se inicia mi aplicación y pronto se bloquea mi instalador de paquetes. Aquí está el registro

03-23 12:12:13.618 8949-8949/com.android.packageinstaller E/AndroidRuntime: FATAL EXCEPTION: main
    Process: com.android.packageinstaller, PID: 8949
    Theme: themes:{default=overlay:system, iconPack:system, fontPkg:system, com.android.systemui=overlay:system}
    java.lang.RuntimeException: Unable to start activity ComponentInfo{com.android.packageinstaller/com.android.packageinstaller.permission.ui.GrantPermissionsActivity}: java.lang.NullPointerException: Attempt to get length of null array
        at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2450)
        at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2520)
        at android.app.ActivityThread.-wrap11(ActivityThread.java)
        at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1363)
        at android.os.Handler.dispatchMessage(Handler.java:102)
        at android.os.Looper.loop(Looper.java:148)
        at android.app.ActivityThread.main(ActivityThread.java:5466)
        at java.lang.reflect.Method.invoke(Native Method)
        at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)
     Caused by: java.lang.NullPointerException: Attempt to get length of null array
        at com.android.packageinstaller.permission.ui.GrantPermissionsActivity.computePermissionGrantState(GrantPermissionsActivity.java:293)
        at com.android.packageinstaller.permission.ui.GrantPermissionsActivity.updateDefaultResults(GrantPermissionsActivity.java:343)
        at com.android.packageinstaller.permission.ui.GrantPermissionsActivity.onCreate(GrantPermissionsActivity.java:100)
        at android.app.Activity.performCreate(Activity.java:6251)
        at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1108)
        at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2403)
        at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2520) 
        at android.app.ActivityThread.-wrap11(ActivityThread.java) 
        at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1363) 
        at android.os.Handler.dispatchMessage(Handler.java:102) 
        at android.os.Looper.loop(Looper.java:148) 
        at android.app.ActivityThread.main(ActivityThread.java:5466) 
        at java.lang.reflect.Method.invoke(Native Method) 
        at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726) 
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)

Creo que el instalador del paquete se bloquea cuando la aplicación intenta mostrar la interfaz de usuario para solicitar permisos. Ya he agregado<uses-permission android:name="android.permission.READ_SMS"/> en mi manifiesto