I wanted to create a Live Debian USB stick (using an existing Debian system). I remember doing such a few years ago with "unetbootin", but when I looked for "unetbootin" via aptitude search, I couldn't find it, so I did a quick "unetbootin debian" search, and found a Debian bug report from 2015 (https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=775689
) that led me to believe I should not use unetbootin, but to use the newer method of simply dd'ing the .ISO to the USB drive.
I walked away then and came back in a few minutes to find it had finished, but didn't pay attention to any other messages, and then tried booting it on another year-old Dell PC. It gave me the grub menu, but then when I tried to boot Debian Live, I got an error about an invalid magic number and a need to load a kernel first.
Not finding any documentation that might help, I checked the md5sum on the downloaded file (it was correct), and tried the dd again. Same result.
I tinkered a bit, and then the next time I tried a dd, I noticed that it was giving me an input/output error for /dev/sdc. Still, it seemed to finish properly, but the boot attempt gave the same failed result.
So I decided to try a different download; I tried the Mate flavor. Same result.
So I decided to try a different USB stick. Same result.
And now, both my sticks are complaining about being mounted read-only, and I can't seem to fix that.
I tried "hdparm -r0 /dev/sdc", and that reports that it's set the read-only flag to off, but the stick still is read-only.
So it appears that dd'ing a Debian .iso to a USB stick, at least using my hardware, bricks the USB stick.
I'm assuming my attempt has cost me two USB sticks, and has just left a bad experience with Debian under my belt, and there's nothing I can do about it. (I don't even know where a bug report might go.) But I thought I'd put this info on the User's list, just for the record, and perhaps at the chance that someone might have a solution.