As of April 12th, you must go to Progress SupportLink to create new support cases or to access existing cases. Please, bookmark the SupportLink URL and use the new portal to contact the support team.
Can you please confirm that you have followed each and every step mentioned in this link for converting the keystore key to a p12? Let me know if this helps. Also, this issue was discussed in detail on this thread. Please review this and see if it helps you to move past the issue. I will also discuss this internally and get back to you with more inputs.