I'm currently migrating from dolphin 7.4.2 to UNA 12. the rest of my sites are just test sites. So until we migrate my site to version 14, there's still a bit of work to do.

Why 12, in recent days.. I was involved with a similar project where we had to migrate from ossn to unacms.. but we migrate straight to the current version we were using... The only challenge we had or consideration was the fact that unacms uses SHA-1 password encryption whereas ossn used MD5 hashing. and we wanted to move the users across. We used a script, but had to in the end let the users be directed to password reset to avoid further complication, other than that, go for RC5.. I think the patches are released and fixed most of the problems... and might just fix the one you currently have.

I tried to migrate directly to recent versions but we lose content due to incompatibility, so now I'm testing with version 12.0.0 and then I will update to higher versions if works. migrating to higher versions I lost the avatars and image headers