iOS application crash while show popover - ios

Question

In application rootviewController allocated like
navigationContr = [[UINavigationController alloc] initWithRootViewController:loginViewController];
loginViewController = nil;
self.window.rootViewController = _navigationViewController;
After login I push MainViewController like this
MainViewController * mainViewController = [[MainViewController alloc]initWithNibName:#"MainViewController" bundle:nil];
mainViewController.isNavigateFromLogin = YES;
/** push the Main screen*/
[self.navigationController pushViewController:mainViewController animated:NO];
mainViewController = nil;
On MainViewController I am adding view of another viewController like this
gridViewControllerObj = [[GridViewController alloc]initWithNibName:#"GridViewController" bundle:nil];
[self.view addSubview:gridViewControllerObj.view];
GridViewController added on button, on button click we showed popover. Code below
Memory allocated to "operationsViewController"
self.optionsPopOver = [[UIPopoverController alloc]initWithContentViewController:operationsViewController];
[_orderOptionsPopOver presentPopoverFromRect:frame inView:self.view permittedArrowDirections:UIPopoverArrowDirectionDown|UIPopoverArrowDirectionUp animated:NO];
This is flow of show popover,if run app on device I see warning print on console. After time out I go back to first view
Issue 1:
BusinessApplication[8321] : Presenting view controllers on detached view controllers is discouraged .
For this case app work but not crash
To fix this warning ,I searched on forum for above warning, there are solution suggested like
AppDelegate *appDelegate = (AppDelegate* )[[UIApplication sharedApplication] delegate];
UIView *rootView = appDelegate.window.rootViewController.view;
After providing rootview to popover above warning goes of
[_orderOptionsPopOver presentPopoverFromRect:frame inView:rootView permittedArrowDirections:UIPopoverArrowDirectionDown|UIPopoverArrowDirectionUp animated:NO];
Issue 2:
After apply of above solution on time out application get crashed.
I got following crash log
BusinessApplication[511] <Warning>: Warning: sync SCNetworkReachability (by-name) query on main thread
mstreamd[513] <Notice>: (Note ) PS: MSSubscriber - 1456278278 Finished retrieving assets. Checking for errors on 0 assets...
BusinessApplication[511] <Warning>: Warning: sync SCNetworkReachability (by-name) query on main thread
BusinessApplication[511] <Warning>: Warning: sync SCNetworkReachability (by-name) query on main thread
BusinessApplication[511] <Warning>: Stack Trace: uncaughtExceptionHandler
(
0 CoreFoundation 0x25f0fd7f <redacted> + 150
1 libobjc.A.dylib 0x33aefc77 objc_exception_throw + 38
2 UIKit 0x29696533 <redacted> + 2918
3 UIKit 0x2969809b <redacted> + 94
4 UIKit 0x293c11a1 <redacted> + 72
5 UIKit 0x29697fcf <redacted> + 198
6 UIKit 0x2949c199 <redacted> + 168
7 UIKit 0x294c5741 <redacted> + 116
8 UIKit 0x294c4721 <redacted> + 120
9 UIKit 0x294037a3 <redacted> + 66
10 Foundation 0x26c16dc9 __NSFireDelayedPerform + 468
11 CoreFoundation 0x25ed6517 <redacted> + 14
12 CoreFoundation 0x25ed6099 <redacted> + 656
13 CoreFoundation 0x25ed4303 <redacted> + 1418
14 CoreFoundation 0x25e21981 CFRunLoopRunSpecific + 476
15 CoreFoundation 0x25e21793 CFRunLoopRunInMode + 106
16 GraphicsServices 0x2d1b1051 GSEventRunModal + 136
17 UIKit 0x29413981 UIApplicationMain + 1440
18 BusinessApplication 0x003ddc17 main + 170
19 libdyld.dylib 0x3408baaf <redacted> + 2
)
BusinessApplication[511] <Warning>: CRASH: Application tried to present modally an active controller <MainViewController: 0x16a78b30>.
BusinessApplication[511] <Error>: *** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: 'Application tried to present modally an active controller <MainViewController: 0x16a78b30>.'
*** First throw call stack:
(0x25f0fd67 0x33aefc77 0x29696533 0x2969809b 0x293c11a1 0x29697fcf 0x2949c199 0x294c5741 0x294c4721 0x294037a3 0x26c16dc9 0x25ed6517 0x25ed6099 0x25ed4303 0x25e21981 0x25e21793 0x2d1b1051 0x29413981 0x3ddc17 0x3408baaf)
ReportCrash[516] <Error>: task_set_exception_ports(B07, 400, D03, 0, 0) failed with error (4: (os/kern) invalid argument)
ReportCrash[516] <Notice>: ReportCrash acting against PID 511
ReportCrash[516] <Notice>: Formulating crash report for process BusinessApplication[511]
mediaserverd[36] <Notice>: '' com.xp.businessApp(pid = 511) setting DiscoveryMode = DiscoveryMode_None, currentDiscoveryMode = DiscoveryMode_None
com.apple.xpc.launchd[1] (UIKitApplication:com.xp.businessApp[0x2b0f][511]) <Notice>: Service exited due to signal: Abort trap: 6
<Warning>: Application 'UIKitApplication:com.xp.businessApp[0x2b0f]' crashed.
assertiond[54] <Warning>: pid_suspend failed for <BKNewProcess: 0x16d885d0; com.xp.businessApp; pid: 511>: Unknown error: -1, Unknown error: -1
assertiond[54] <Warning>: Could not set priority of <BKNewProcess: 0x16d885d0; com.xp.businessApp; pid: 511> to 2, priority: No such process
assertiond[54] <Warning>: Could not set priority of <BKNewProcess: 0x16d885d0; com.xp.businessApp; pid: 511> to 4096, priority: No such process
UserEventAgent[17] <Warning>: id=com.xp.businessApp pid=511, state=0
ReportCrash[516] <Notice>: Saved report to /var/mobile/Library/Logs/CrashReporter/BusinessApplication_2015-03-14-171423_IPad.ips
locationd[60] <Notice>: Gesture EnabledForTopCLient: 0, EnabledInDaemonSettings: 0
locationd[60] <Notice>: Gesture EnabledForTopCLient: 0, EnabledInDaemonSettings: 0
mstreamd[513] <Notice>: (Note ) mstreamd: Not monitoring for external power.
mstreamd[513] <Notice>: (Note ) PS: Media stream daemon stopping.
mstreamd[513] <Notice>: (Note ) AS: <MSIOSAlbumSharingDaemon: 0x14e30790>: Shared Streams daemon has shut down.
mstreamd[513] <Notice>: (Warn ) mstreamd: mstreamd shutting down.
<Notice>: Gesture EnabledForTopCLient: 0, EnabledInDaemonSettings: 0
<Notice>: Gesture EnabledForTopCLient: 0, EnabledInDaemonSettings: 0
locationd[60] <Notice>: Gesture EnabledForTopCLient: 0, EnabledInDaemonSettings: 0
locationd[60] <Notice>: Gesture EnabledForTopCLient: 0, EnabledInDaemonSettings: 0

Answer 1

The problem in what you're doing is that you've created a pitfall chain for yourself.
You create a couple of controllers, and present them, but after you present them, you deallocate them. You can't present something you deallocate. This leads to the first issue, trying to present another controller when your current controller is nil.
Next, you take the error message and search for a solution out of context. That is not a solution to your problem and obviously it will lead to a crash if you try and use it.
The first thing you need to do is to remove the nil assign. I don't know why you're doing it and I'm certain its causing many problems.
When you have *a = *b, and *c = *a, if you set c = nil, all of the rest of the variables will be nil as well because its how pointers work. I'm happy to help you some more if you don't mind somebody looking at your code, but I can't do much if problematic calls are still in there.