I'm also experiencing this issue, I'm not a US based user, and when I resumed my purchase in the sandbox, it reported an error that readsError Domain=SKErrorDomain Code=0 "发生未知错误" UserInfo={NSLocalizedDescription=发生未知错误, NSUnderlyingError=0x303bae790 {Error Domain=ASDServerErrorDomain Code=5002 "出現未知錯誤" UserInfo={NSLocalizedFailureReason=出現未知錯誤}}}