iOS: How can I make the IAP sandbox forget the wrong login name?
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In setting up the IAP sandbox for testing my app I followed the lengthy procedure for creating a new sandbox login but toward the end of the procedure I made a mistake. A screen asked my to confirm my login/password without saying what login it wanted and I (incorrectly) gave my normal Apple login and password. It rejected it saying something like "not a sandbox login". But now every time my app goes to login to the sandbox it puts up a login dialog with the user name already filled in and just the password field blank. But it's filled in with the wrong user name.  I don't know where it's getting that user name from. I made sure I'm logged out of everything I can think of (iCloud, store, and game center) but it still knows that user name. I rebooted the phone but that didn't help.

How can I make the IAP sandbox forget the wrong user name?