The backup GPT table is corrupt, but the primary appears OK, so that will be used.

after reading the two posters above me and re-reading the whole log (it was longer than I thought) there is so much strangeness going on from residues of old data I wonder if you should just bite the bullet and let DD zero this disk out a few hours then start over? maybe fsck could some of the lifting?
I can't escape the conclusion it's no good to do anything on this disk without a serious scrub. 2 cents

    brent No ... !!!! - misunderstood - Solus iso is not unclean !! It seems to be permission problems then, why GParted is wiggy ... These permission problems could be caused by my password ... ?!

      brent ... dd if=/dev/zero of=/dev/<partition> ... would be the solution, but I don't know if this 256 TB size would then melt ... ?!?!?! How long would this last ?! When USB-cable has speed with 25 MB/sec. then it would take 77 days ?!

          craigtoyoracer I am sad, when it is really hard-coded ... when I created successfully a partition then there pops up a new "undefined" file-system with size of 1 MB ... - well, then there is spyware or what as firmware ... ?!

              brent I can't escape the conclusion it's no good to do anything on this disk without a serious scrub.

              I agree. I've been there before, and at some point, the time and effort to do a reinstallation is far less than dealing with continuing problems. Fortunately, Solus is very fast and easy to install and update.

                  DirtyAngel when I created successfully a partition then there pops up a new "undefined" file-system with size of 1 MB ... - well, then there is spyware or what as firmware ... ?!

                  spooky and unacceptable. never seen gparted do this. although that's about the size of a grub boot partition...
                  I am as reasonably paranoid as the next PC user and firmware malware is the next big attack vector (from my reading) so ya never know.

                  DirtyAngel but I don't know if this 256 TB size would then melt ... ?!?!?! How long would this last ?!

                  if it is truly is 256TB (did you verify?) then leave the computer on and check progess daily. I would guess 20 hours but I have nothing to base that on.

                  WetGeek I agree. I've been there before, and at some point, the time and effort to do a reinstallation is far less than dealing with continuing problems. Fortunately, Solus is very fast and easy to install and update.

                  too much monkey business on this SSD🙂, yes

                        pokmu 256 TB drives don't exist, and they especially do not exist for 25 Euros. Scammers will sell hard drives and flash drives rigged to report they hold more than they actually do, when in reality they're much smaller cheap drives.

                        ⬆️This.
                        There is absolutely no way that's a real hard drive capacity. Especially not at this price. There are tools like f3 to confirm the actual size of a drive

                        f3 usage: https://www.linuxbabe.com/command-line/f3-usb-capacity-fake-usb-test-linux
                        current hard drive capacities: https://www.techradar.com/best/large-hard-drives-and-ssds

                        Edit: if it's an external drive there is also a good chance that it's just a USB flash drive inside an HDD case.

                          It seems that GParted is not working correct ? Re-install did not help. The error messages stay the same.
                          Error message is about GPT-table :

                          "Libparted-Error
                          The backup GPT table is corrupt, but the primary appears OK, so that it will be used."

                          Please fix this in GParted.

                            DirtyAngel It seems that GParted is not working correct ?

                            That seems quite unlikely to me, but you could check it by installing KDE Partition Manager. It's similar enough that you shouldn't have trouble using it. If you get a similar result with it, you'll have a better idea what's wrong.

                              DirtyAngel The only thing that's not working correctly is your fake drive. They of course had to do some trickery to make it report as a 256 TB drive, so that's most likely what trips gparted up.

                                The same behaviour in GParted
                                with described Libparted -error
                                and because of corrupted GPT-partition-table ...
                                happened already two years or three years ago.
                                (I don't know If this was a Virus in GPT-partition-table.)

                                Yeah.You are right ... This is a monkey-SSD.