<Since the customer support web page also has this problem, the forum was the only way to inform Keil of this issue>
We were unable to license our PK51 toolset because the licensing web page rejected our email address as being invalid.
This is possibly due to the fact that our POP3 email recently changed to require authentication.
Trying to report this issue to Keil, we found that the customer support web page did the same authentication of the email address, thereby not allowing the support comment to be logged.
Finally, we used an 'acm.org' email to obtain the license.
Please investigate, for the sake of other users.
Best regards Ed Kuzemchak Software Design Solutins, Inc.