Possibilities to update UCS 4.3 to a more current version

Good afternoon friends, I got a client that had the version of UCS 4.3-errata0 installed and that is having rpc problem and lack of connection between stations, fileserver (Samba4 client) and is not even logging into his administrative panel.

This client has dozens of users registered in AD, several ACLs configured in the fileserver, which would make it impossible to install the domain from scratch, so I would like to know from friends if there is any way I can generate a backup of this UCS 4.3 and restore in an installation from scratch by example.

Another option I thought of would be to try to migrate the Domain Controller to a Windows Server, since I tried to add another UCS to pull the Domain Controller option for it, but the UCS did not let it integrate because they are different versions, but I saw that the UCS only has support to pull the Windows Server DC, but searching I didn’t find a way to migrate a domain from UCS to Windows Server.

I thank you in advance for any help you can give me.

PS: I’m not able to upgrade the UCS version either. =(