Your comments

My issue is resolved. I just got the correct private key - certificate pair to create .p12 files. Hope the messages will help for the others. Now I have another issue and I'm opening a new topic for that :)
According to here:

http://forums.adobe.com/message/42119...

I must find that private key. Now I'm looking for it. I'll update the topic accordingly.
Now I created a new app and followed the instructions on your webinar but it failed again with the same error message.

I think I produce a wrong .p12 file. I'm a member of a development team and we already have a distribution certificate for our company. So I didn't need to create and upload a CSR.

So I was putting the .p12 file that I produced from my development certificate. Obviously that was a mistake: using the company's distribution provisioning profile and my development certificate.

So that now I don't have the private key for our company's distribution certificate. What shall I do?
If we are sure that it's because of the provisioning profiles and certificates I can share the Apple Developer credentials with you via email.
Now I updated my Apple App ID to wildcard, but it failed again.

My RareWire App ID is 598.
I think the solution that you address is for the error message: 'failed_openssl_p12_to_pem'

__________

The error message now I'm having is 'failed_xcode_build'

I followed the tutorial, sharing these tutorials is very thoughtful of you and thank you for the fast reply :)