Hey guys. Off course I tried Disks and "Format". But, like I told you, it did not work sofar. At this moment I am following the suggestion of Just. We will see.

I'm no doctor house, but my diagnosis is write-protected.

(Am I the only one that's been thru these identical situations with malfunctioning drives and a deeper look reveals I have no permission to write to it in the first place? I think it's just me🙂)

Open gparted and make a new partition table on it. Then create a partition. Done.

Shugart
Quick & dirty format.
The allmighty wiki says:

A partition table is a table maintained on disk by the operating system describing the partitions on that disk

Creating a new one means that the old one gets erased ---> the bits on the usb stick do not change (ie: whatever was on the key is still there) but cannot be (at least easily.....) accessed by the OS.
With a new partition you can start writing with impunity on the now, seemingly empty, filesystem, effectively overwriting whatever was on it before.

    So far, I tried everything, but nothing works. The USB must be corrupt. Only 1 solution : throw it away and buy a new one. Anyway, everybody thanks for any help. And have a nice weekend.
    Greetings, Evert.

      evert So far, I tried everything, but nothing works. The USB must be corrupt. Only 1 solution : throw it away and buy a new one.

      Since USB 2.0 thumb drives these days cost less than a small bag of potting soil, one could be forgiven for saying that they're "cheaper than dirt.' Literally. Sounds like you've already tried hard, and everything that should have worked didn't. I think you're well advised to dump it and buy a new one.

      If your device has more than one USB port, though, and you've done everything in the same port so far, take a moment to try a different port before you give up totally. It's not common, but it IS possible for one port to fail and others to keep working fine.

      I believe you mentioned it's an older USB thumb drive, which is why I mentioned USB 2.0. If your device has USB 3.0 ports, those are not much more expensive, and they are way faster and hold much more data.

          WetGeek It's a 3.0 USB and I did try more ports. But thanks for trying to help.

            Sometimes they do die 🙂 I mean for $5 to $15, what do you expect ? 😅

              dbarron Frugal side of me says meh. My expectations for $15 far exceed my expectations for $5. $15 is not chump change. $10 either. Would try to restore drive life any way I could at that price. $5 not so much.
              evert Before dispatching a dead usb drive, I give it a few good whacks with a hammer. Habit.

                    brent lol Umm yes, I'm sure that's good for delicate electronics 😀 I understand though Brent (lol).