I'm using MKNetworkkit to parse XML data to the server. Before Entering into the success block its gets crash with EXC_BAD_ACCESS with out any reason and am already done with NSZombieEnabled like all the stuffs.![Below is the screen shot of where its getting crash.][1][1]: http://i.stack.imgur.com/FL3l9.png
You may find this useful to help debug http://subhb.org/2012/07/02/how-to-debug-exc_bad_access-error/
You will get EXC_BAD_ACCESS error mostly in the following scenarios:
You are trying to access an object that is not initialized.
You are trying to access an object that no longer exists. Either it’s being released or it’s nil. In ARC mode, make sure you take
ownership of the object that you want to use.
You are passing an message to an object that the object doesn’t understand. It can also happen for bad typecast.
Have you tried running breakpoints on your code and stepping through your program line by line and seeing if any of the above match the result?
Related
I am facing this weird random crash where I get EXC_BAD_ACCESS on an object that exists. I am totally stumped on why this is happening. The code in the image executes without any issues 99.99% of the time. I saw this crash second time and that when I thought I should figure out what might be going wrong. I am executing this code on the main thread and the crash line has two core data objects. This shouldn't be a concurrency issue because it's only used in this class. Scary part is that object is there, values are there, still, I am getting EXC_BAD_ACCESS. Any ideas why this might be happening?
Let me know if you guys need more info. And thanks in advance for your help. :)
EDIT 1
Definition of Employee and EmployeeForTask (the class declarations are empty and has no variable defined in it, it just inherits from NSManagedObject)
You should enable NSZombies. Zombies helps to detect these kind of crashes by logging problem in console. you can enable zombies by :Click on Product⇒Edit Scheme to open the sheet and set the Enable Zombie Objects check box
When building app on real device then disable Zombies. Otherwise app will not run on device.
So I'm using AWS Cognito to authenticate my users from my iOS application. However in a small bit of code, I've narrowed down an extremely odd problem while making some minor changes.
I noticed that I was receiving this error:
Unable to refresh. Error is [Error
Domain=com.amazonaws.AWSCognitoCredentialsProviderErrorDomain Code=1
"identityId shouldn't be nil"
UserInfo={NSLocalizedDescription=identityId shouldn't be nil}]
After debugging, I've noticed the identityId actually does not get set:
_identityId = [jsonDict objectForKey:#"IdentityId"];
self.keychain[EncryptionKeyKey] = self.identityId;
return [AWSTask taskWithResult:nil];
Though I clearly set it in the above code block, and checked to make sure that [jsonDict objectForKey:#"IdentityId"] did produce some value, I found through the debugger that a "po self.identityId" before and after the assignment is still nil. NSString isn't something that needs to be allocated, and what's weirder is that this used to work. I switched some statements up because of my current use of UICkeychainstore but that shouldn't affect anything. In addition, I disposed of my changes and saw that the problem still exists. Please let me know if you have any ideas.
I'm also noticing this error shortly after the previous error:
This application is modifying the autolayout engine from a background thread, which can lead to engine corruption and weird crashes. This will cause an exception in a future release.
any ideas would be very helpful
Turns out that I had both a login method and a getToken method. In the getToken method I wasn't doing something right based on some changes I had made to the code to use keychain instead of nsuserdefaults for security reasons. After fixing the getToken it worked. After further debugging though, I saw that identityId still doesn't get set regardless of it working or not. I guess it might be some sort of block variable s.t. the assignment doesn't happen immediately. At least that's my theory. All in all it works though.
From time to time, Xcode Crashes comes up with a crash that i cannot understand. I pasted the xccrashpoint to gist
It states, that Thread 12 crashed somewhere in CoreGraphics called by CorePDF, called by QuartzCore drawing some layers. This seems like OS-called code, maybe via thread 1 which is doing _saveSnapshotWithName. So i assume, that this happens when closing the app.
Does anyone have at least a rough idea what is going on here? Maybe someone saw something similar before and can give a hint about what is crashing…
There is nothing special in the app that would cause dramatically wrong behaviour when leaving the app (-> when a screenshot ist taken).
Exec bad errors occur when an attempt is made to access a object or memory location which is not yet initialized.
There might be a problem with an object which you are not defining global.
Check if there is any object you defining and initializing in a method and trying to access out of the scope.
For more details related to errors and crashes, please go through below link.
http://www.raywenderlich.com/10209/my-app-crashed-now-what-part-1
Testing my app which gets location data from an api and displays in a table view. Was testing something else today and app crashed - EXC_BAD_ACCESS (code=1, address=0X0). What does this mean and how do I read the information provided by Xcode to figure out how to fix?
EXEC_BAD_ACCESS usually means that you are trying to access an object which is not in memory or probably not properly initialized.
Check in your code,
if you are accessing your Dictionary variable after it is somehow removed?
is your variable properly initialized? You might have declared the variable but did not initialize it and accessing it.
There could be a ton of reasons and cant say much without seeing any code.
Try to turn on NSZombieOjects - this might provide you more debug information. Refer to here How to enable NSZombie in Xcode?
IF you would like to know where and when exactly is the error occurring, you could check for memory leaks using instruments. This might be helpful http://www.raywenderlich.com/2696/instruments-tutorial-for-ios-how-to-debug-memory-leaks
Based on the information you provided. My guess is that the library is calling out to a block you provided. Inside that block is a Dictionary which has something wrong with it.
Good luck!
I have the following crash log and code to go along with it:
https://gist.github.com/emilevictor/7422ac293eb27b415fb8
I'm a bit confused, as I have wrapped this Core Data code (which creates a new instance in the database) with a try catch block but it is still crashing out occasionally in on release compiled code.
This is on a device which has had its local data wiped and installed from scratch, by the way.
I'm not sure what else to do, I assume that this code might have an issue.
First the try/catch problem. #try/#catch only trap NSExceptions which have been #thrown or -raised. You don't have this kind of exception, you have a segfault. These happen at a much lower level and cannot be trapped in a #try/#catch.
The real problem here is what's going wrong to cause the segfault. Usually this is caused be objects which have been prematurely -dealloced or by notifications being sent to -dealloced observers. I can see from your call stack that the process is in the middle of sending a notification, so my guess it the second type.
Somewhere, you have registered an observer and that observer has gone out of scope (-dealloced) without unregistering itself. I would start by profiling the app for zombies.