Masfenix, thank you for the reply I am trying your suggestion first. I'm a little new at working with the code behind, so here is what I tried (not quite working yet).
I am logged on with my username which gives me access to the admin page where I am trying to change user JohnDoe's email
On that admin page I put a textbox with ID of "TxtBxNewEmail", a textbox with ID of "UserName" , and a button with ID "BtnUpdateUserEmail"
In the code behind page I put the following subroutine in the click event:
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Dim user As MembershipUser
user = Membership.GetUser(UserName)
user.Email = TxtBxNewEmail.Text
Membership.UpdateUser(user)
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Then when viewing the admin page while logged on under my username, I type JohnDoe in the UserName text box, the JohnDoe's new email in the NewEmail text box and click on the button.
I get the error: The provider user key supplied is invalid. It must be of type System.Guid.
Parameter name: providerUserKey
I think It is very likely I implemented your suggestion incorrectly -- is that the problem? Or am I running into trouble because I am logged on as me and trying to change JohnDoe's profile?
Thank you for your assistance.