the key made with the startup disk creator does not work, even on old hardware. nevertheless, simply copying the whole iso image on a key works.
thus, workaround (as root or sudo):
dd if=ubuntu-15.10-desktop-amd64.iso of=/dev/sdX bs=16M ; sync
replace "X" with your usb key letter, see eg dmesg or blkid, end then eject the drive. for "X" do not include any partition numbers.
the key made with the startup disk creator does not work, even on old hardware. nevertheless, simply copying the whole iso image on a key works.
thus, workaround (as root or sudo):
dd if=ubuntu- 15.10-desktop- amd64.iso of=/dev/sdX bs=16M ; sync
replace "X" with your usb key letter, see eg dmesg or blkid, end then eject the drive. for "X" do not include any partition numbers.