If you are getting "invalid token" error on
confirming email using UserManager.ConfirmEmailAsync, then there might
be two reasons:
Reason #1 : The Call back Url is modified by browser.
Solution : Try doing Encode Callback Url before sending in mail.
string code = HttpUtility.UrlEncode(UserManager.GenerateEmailConfirmationToken(userID));
Reason #2 :
The Confirmation token (UserManager.GenerateEmailConfirmationToken) is
generated on one server and the mail confirmation code is on another
server.
Solution : As confirmation token is generated using
machine key and security stamp, so the machine key should be consistent
on both server. So add same machineKey under system.web
in
configuration file of both the application as below:
<system.web>
<machineKey validationKey="883A787F3B793567817EA540DCA4285B1A695C58A38B3493E1E69821148E5E6B5032F61813DF81B9731AB5F8AF7ECA3A75429E38D6513408E86ED4AC77243439" decryptionKey="7F0884CE1698D23538D4FC3670FD122FCF856645518617B7" validation="SHA1" decryption="Auto"/>
</system.web>
Machine validation key and decryption key can be generated using iis.
