Greetings Gilles Caulier,
Have solved the problem.....After disabling practically all the options in the settings of the Motherboard (MSI 970A-G43 MS-7693(V3.x)) I reinstalled Mageia-6-sta-2-x86_64-DVD.iso using a previously installed HDD thereby using the the autoalloacated patitions, which would not allow me to do previously claiming the partitions: /, Linux swap and /usr, were to small (under 8.4GiB each). This done under "expert mode". At the end of the installations it further installed the "Grub2" boot system and the tried to add an additional entry which surly had to do with the UEFI, which I deleted. I booted Mageia 6 and proceeded to install mi WiFi, them did the updates, all before opening Digikam. Then, using Dolphin copied the picture files from sdb1 to /home/egh/Pictures in sda7 This went OK. Having completed this, I opened Digikam and followed the opening prompts which found the path /home/egh/Pictures, but I still could not open them. On further exploring, found a new slider at the bottom right corner of Digikam which starting showing an incremental percentage figure which was a new copying into Digikam. On completion of 100% I opened the picture list to find they were all there; all 411 folders with their pictures in them......Hooray, after a lot of fiddling!
Thanks for all your help and have a nice weekend.