HTTP Web Server: Lotus Notes Exception - There is no certificate in the Address Book

Hi.

I have configured an user in the names and address book, in his people document, setting the “Force user to change Internet Password on next login:” parameter to “Yes”.

When the user login to the web site (intranet) the ChangePassword page appears. The user types the old password , New password , New password (confirmation) and press the Submit button and get the message “HTTP Web Server: Lotus Notes Exception - There is no certificate in the Address Book.”.

What is wrong?

Any idea???

I hope your help