I tried for several hours without find any solution. My problem is similar (or the same); I need to define a SSL certificate for each site of my subdomain i.e.:
main domain name: www.tryme.it
[... and so on ...]
I discovered that if I create a certificate SELF-SIGNED for the first domain (doesn't matter what is the first, I mean: the first used for SSL...) the certificate will be stored inside the SSL folder, i.e.:
well, all is ok and for that domain all works correctly.
But when I try to create another certificate for another domain ISPConfig tells me that 'there is another certificate for this IP address'.
But if I try a connection to a different site, i.e.:
the certificate proposed and used is the same of sub1 (see example above).
This situation could be replicated so that I believe this is very frustrating and limitating (infact I manage another domain with Plesk and for each domain I can create certificates without problems).
My colleague says that the creation certificate process have not to be based on IP address but instead on site name.
I'm not expert in this then I wait for an answer and to understand if there is a solution to apply, otherwise I'll be forced to look for another CP.
Thank you very much!