IOS in-app purchases stopped working suddenly, fetching null identifiers -

my in-app purchases working until yesterday , today submitting app review. change made in app page in itunes, connected app (by checking) in-app purchases.

from time, every time try in debug app buy test account, getting error:

nsinvalidargumentexception', reason: 'invalid product identifier: (null)' 

i have already:

1. re-installed app
2. logged out store , used again test account

but today nothing seems work. exact same code working perfect yesterday, same test account.

may because did change in itunes? worrying happen when app gets approved , goes online.

any appreciated.

edit:

the problem array _products stays nil.

- (void)reload {     _products = nil;     nslog(@"reload called");     [[vimaiaphelper sharedinstance] requestproductswithcompletionhandler:^(bool success, nsarray *products) {         if (success) {             _products = products;             nslog(@"success appstore");         }     }];     (skproduct* product in _products) {         nslog(@"in-app item:%@",product.localizedtitle);     } } 

the success log message never called. yesterday had no problem, same code.

edit: after lot of tries, works. without changing anything. seems server takes lot of time respond back. however, cannot buy product since "cannot connect itunes". why might happen?

edit2:

in other tries, problem seems in code:

pragma mark - skproductsrequestdelegate

- (void)productsrequest:(skproductsrequest *)request didreceiveresponse:(skproductsresponse *)response {      nslog(@"loaded list of products...");     _productsrequest = nil;      nsarray * skproducts = response.products;     (skproduct * skproduct in skproducts) {         nslog(@"found product: %@ %@ %0.2f",               skproduct.productidentifier,               skproduct.localizedtitle,               skproduct.price.floatvalue);     }      _completionhandler(yes, skproducts);     _completionhandler = nil;  } 

after loop. especially, bad_access in line: _completionhandler(yes, skproducts);

a problem xcode 5 simulator has been reported not fixed. see this post describing situation.