My friend
I have same problem
Hi all,
I updated my iPhone (4s/64Gb) to iOS 5.1 this morning - the update process went smoothly, but now the iPhone has started asking for my iTunes account password pretty much every time I launch an application or return to the home screen. When I enter the password, the device thinks about it for a moment or two and then returns the following error:
*This is not a Test User account.*
+Please create a new account in the Sandbox environment.+
+[Environment: Sandbox]+
I know that the Sandbox environment is for developers testing stuff out, but I've never done any development for the iPad/iPhone/iPod and don't have any tools or settings for that. I've also seen references online to this error being related to having jailbroken the device and subsequently applying an update, but I've never done this - my iPhone has been plain vanilla flavour all along.
I'm a bit stumped - I have no idea what the device thinks it's doing, and consequently no idea how to stop it from doing it. Does anyone have any suggestions?
Thanks in advance for your help!