UBB.threads PHP Forum Software Community Forums UBB.classic UBB.classic 6 Support can I install this way...

I'm considering changing my forum from Domain-A to Domain-B and get rid of Domain-A all together. If so, I'd like to do a new install of UBB6 on Domain-B, but transfer over the member files from Domain-A so no one has to re-register. Domain-A is still running 5.47, I haven't upgraded it yet. Would this be a problem?