IAP sandbox test error:cann't connect to itunes store

These days when I test IAP with sandbox account,it always turns out SKPaymentTransactionStateFailed,and the error.userInfo is "cann't connect to iTunes Store".The step is:
  1. I can search the product with productId

  2. then call pay method,and then got a SKPaymentTransactionStatePurchasing delegate

  3. then promt a sandbox password field.

  4. After I filled the password, it turns out SKPaymentTransactionStateFailed,the error info is "cann't connect to iTunes Store"

Everything goes well before,and I haven't change any code,Anyone could help me?
Same here. I'm getting the same error. Anyone has an idea why?
It works ok now. so it's due to the Apple service problem
IAP sandbox test error:cann't connect to itunes store
 
 
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