Domain=NSURLErrorDomain Code=-1202 "The certificate for this server is invalid. You may be connecting to a server masquerading as a "auth-sandbox.itunes.apple.com", which threatens the security of your confidential information. "
In app purchase sandbox unavailable
Did you manually set the clock on the device? This kind of issue can happen if you move devices clock back or forward in time too much (for example for testing purposes)
Also I would check if a VPN is enabled and try again after disabling it (Settings -> General -> VPN & Device Management).