Very grateful to you for your efforts Cory. I finally got a result - and this must be a warning to others because I count myself blameless. Looking through past problems of this nature, there was a case where caps lock button was accidentally set, and so the password was not recognised. I decided to check that, and found that mine was clean of caps lock possibility. While testing the caps lock idea, going through the procedure for the Nth time, I saw something odd. There is a screen that says 'If you have forgotten your pw continue'. Below, but before the continue button there were three options one of which was 'I forgot my password" pre-selected as the default. Well, I didn't forget my pw - I got it dead right but it was being refused. So, on all my attempts I was choosing the option 'My password is refused at startup ' (not verbatim - I forget). It was a very long shot, because if you choose anything but the default "I forgot my pw" you should not be using those options, because the intro information for that page is incompatible with the page contents. However, choosing the default solved the problem -- I think. To be sure of not misleading you, I should add that the password I had been trying to establish is complex - meaningless, and with upper and lower case. As this takes time and special care, I chose a very simple one - expecting failure once again - but it worked. The complex one is the same as that used on my Mac Pro, which changed with no problem at all, and it is also on Mojave 10.14. I hope I have not wasted your time and that knowing of this loophole might be useful. Thanks again. Ed Singer
