Problem solved, thanks to everyone's help.
I am embarrassed to tell y'all the truth. If I had read the preliminary installation instructions instead of forging ahead I could have saved everyone a lot of trouble.
They said:
(1) Use Custom partitioning
(2) The root partition (sda5) has to be greater than 15 GB (I used 20 to be on the safe side)
(automatic partitioning only allows 12GB for the root partition and I have to admin the error message wasn't very helpful, but what the heck, I learned a lot which is one of the reasons I wanted to install Linux in the first place!)
When I did that all fell into place.
I hope I become proficient enough to be of help to everyone in these forums. They must be a labor of love....
Thank you everyone, again!
Kent G. Bailey