Thanks for your help, not much could be found, did the next best thing, wiped the drive. I installed Catalina 100 Gb gone, I run on an external, internal is original. {2018 mini}. At 75 years of age I do not appreciate Apple screwing things up when they change OS. I have been with Apple since Leopard or earlier, If they can't figure how to make things work leave it the hell alone. Tom