Getting crash in ios7 _UINavigationBarBackIndicatorView - iphone

Question

The code below is working fine in ios6 but getting crashed in ios7. What is the reason i am not getting. Below posting the code and the error message i am getting.
-(void)viewWillAppear:(BOOL)animated
{
[NSThread detachNewThreadSelector:#selector(showLoading) toTarget:self withObject:nil];
if ([[NSUserDefaults standardUserDefaults] boolForKey:#"isBannerShown"]) //-ive logic is applied
{
[self.adBannerView setHidden:YES];
[self.adBannerView setDelegate:nil];
}
if([Manager getInt]==3)
{
Animation *objAnimation = [[Animation alloc]init];
self.hidesBottomBarWhenPushed = YES;
[self.navigationController pushViewController:objAnimation animated:NO];
}
[self.navigationController.navigationBar setHidden:NO];
[self.navigationController.navigationBar setBackgroundImage:[UIImage imageNamed:#"setting.png"] forBarMetrics:UIBarMetricsDefault];
btnRefresh = [UIButton buttonWithType:UIButtonTypeCustom];
[btnRefresh setFrame:CGRectMake(280,9,33,31)];
[btnRefresh setBackgroundImage:[UIImage imageNamed:#"refresh.png"] forState:UIControlStateNormal];
[btnRefresh addTarget:self action:#selector(btnRefreshPressed) forControlEvents:UIControlEventTouchUpInside];
barButtonRefresh = [[UIBarButtonItem alloc] initWithCustomView:btnRefresh];
self.navigationItem.rightBarButtonItem = barButtonRefresh;
[self createTable];
if(viewMessage)
{
[viewMessage removeFromSuperview];
}
viewMessage= [[UIView alloc]initWithFrame:CGRectMake(6,8,307,screenSize.height - 110)];
[viewMessage setBackgroundColor:[UIColor blackColor]];
[viewMessage setAlpha:.7];
[contentView addSubview:viewMessage];
[self createView];
[viewMessage setHidden:YES];
[contentView bringSubviewToFront:adBannerView];
float width = [Manager getImageWidth] ;
float height = [Manager getImageHeight];
count =0;
if(imgViewFullImage)
{
[imgViewFullImage removeFromSuperview];
}
imgViewFullImage = [[UIImageView alloc]initWithFrame:CGRectMake(0,0,width,height)];
[imgViewFullImage setBackgroundColor:[UIColor blackColor]];
[imgViewFullImage setContentMode:UIViewContentModeScaleToFill];
[self.view addSubview:imgViewFullImage];
[imgViewFullImage setHidden:YES];
UIImageView *imgHeader = [[UIImageView alloc]initWithFrame:CGRectMake(0,0,320,44)];
[imgHeader setImage:[UIImage imageNamed:#"connect-req1.png"]];
[self.navigationController.navigationBar addSubview:imgHeader];
UILabel *lblHeader = [[UILabel alloc]initWithFrame:CGRectMake(80,8,200,30)];
[lblHeader setBackgroundColor:[UIColor clearColor]];
[lblHeader setTextAlignment:UITextAlignmentLeft];
[lblHeader setTextColor:[UIColor whiteColor]];
[lblHeader setFont:[UIFont boldSystemFontOfSize:19.0]];
[lblHeader setText:#"Connect Requests"];
[self.navigationController.navigationBar addSubview:lblHeader];
btnRefresh = [UIButton buttonWithType:UIButtonTypeCustom];
[btnRefresh setFrame:CGRectMake(280,9,33,31)];
[btnRefresh setBackgroundImage:[UIImage imageNamed:#"refresh.png"] forState:UIControlStateNormal];
[btnRefresh addTarget:self action:#selector(btnRefreshPressed) forControlEvents:UIControlEventTouchUpInside];
[self.navigationController.navigationBar addSubview:btnRefresh];
[self createTable];
if(viewMessage)
{
[viewMessage removeFromSuperview];
}
viewMessage= [[UIView alloc]initWithFrame:CGRectMake(6,8,307,screenSize.height - 110)];
[viewMessage setBackgroundColor:[UIColor blackColor]];
[viewMessage setAlpha:.7];
[contentView addSubview:viewMessage];
[self createView];
[viewMessage setHidden:YES];
[contentView bringSubviewToFront:adBannerView];
}
Error:
[_UINavigationBarBackIndicatorView setAlpha:]: message sent to
deallocated instance 0x10e43760
update : found crash.
case 4:
{
btnMoreSelected=NO;
[Manager setInt:1];
[tabBar setSelectedIndex:2];
[imgMore setImage:[UIImage imageNamed:#"more.png"]];
[imgMyConnection setImage:[UIImage imageNamed:#"connect-req-hover.png"]];
[imgIceBreaker setImage:[UIImage imageNamed:#"my-ice-brkr.png"]];
[imgSetting setImage:[UIImage imageNamed:#"settings-nav.png"]];
[imgSearchView setImage:[UIImage imageNamed:#"search.png"]];
[imgSearchSeparator setHidden:NO];
[imgSettingSeprator setHidden:NO];
[imgIceBreakerSeparator setHidden:YES];
[imgMyConnectionSeprator setHidden:YES];
}
It is crashing here [tabBar setSelectedIndex:2];
Thanks in advance.