ios - Simulator not getting location -

i'm following this tutorial learn core data. i'm on section 4, adding events. in section 2 tutorial says add button become active seconds after prompted simulator location, never becomes active, idea might happening?

ps: if hardcode button active before getting location following error:

*** terminating app due uncaught exception 'nsrangeexception', reason: '*** -[nsmutablearray objectatindex:]: index 0 beyond bounds empty array' 

on following line:

[self.tableview insertrowsatindexpaths:[nsarray arraywithobject:indexpath]                           withrowanimation:uitableviewrowanimationfade]; 

edit: posting more code bigger picture

- (void)viewdidload {     [super viewdidload];      self.title = @"locations";      self.navigationitem.leftbarbuttonitem = self.editbuttonitem;      addbutton = [[uibarbuttonitem alloc] initwithbarbuttonsystemitem:uibarbuttonsystemitemadd target:self action:@selector(addevent)];     addbutton.enabled = no;     self.navigationitem.rightbarbuttonitem = self.addbutton;      [[self locationmanager] startupdatinglocation];      eventsarray = [[nsmutablearray alloc] init];  } 

this method there error:

-(void)addevent{     cllocation *location = [locationmanager location];      if(location){         return;     }      event *event = (event *)[nsentitydescription insertnewobjectforentityforname:@"event" inmanagedobjectcontext:managedobjectcontext];      cllocationcoordinate2d coordinate = [location coordinate];     event.latitude = [nsnumber numberwithfloat:coordinate.latitude];     event.longitude = [nsnumber numberwithfloat:coordinate.longitude];     event.creationdate = [nsdate date];      nserror *error;     if (![managedobjectcontext save:&error]) {      }      [eventsarray insertobject:event atindex:0];     nsindexpath *indexpath = [nsindexpath indexpathforrow:0 insection:0];     [self.tableview insertrowsatindexpaths:[nsarray arraywithobject:indexpath]                           withrowanimation:uitableviewrowanimationfade];     [self.tableview scrolltorowatindexpath:[nsindexpath indexpathforrow:0 insection:0] atscrollposition:uitableviewscrollpositiontop animated:yes];  } 

and appdidlaunch method:

- (bool)application:(uiapplication *)application didfinishlaunchingwithoptions:(nsdictionary *)launchoptions {     rootviewcontroller *rootviewcontroller = [[rootviewcontroller alloc] initwithstyle:uitableviewstyleplain];     navigationcontroller = [[uinavigationcontroller alloc] init];      nsmanagedobjectcontext *context = [self managedobjectcontext];      if(!context){      }      rootviewcontroller.managedobjectcontext = context;      [self.navigationcontroller pushviewcontroller:rootviewcontroller animated:no];      [rootviewcontroller release];      [self.window addsubview:navigationcontroller.view];     [self.window makekeyandvisible];      return yes; } 

there no nsmutablearray in code posted. problem error trying access object (at index 0) in empty nsmutablearray. find array, , find problem.