Can't format USB drive partition from Ubuntu 16.04 Disks apps

Solution 1:

Often the tools that create USB flash drives use dd or dd underneath to create a hybrid DVD/flash drive installer. That does not have a standard partition table, so then many partition tools do not correctly see flash drive. You usually can just erase with dd the beginning of drive where partition table is and then standard partition table tools like gparted, parted or fdisk will then work.

Reset USB flash that was dd'd to make it usable again, reuse

Formatting a USB stick - unable to operate USB &

https://help.ubuntu.com/community/mkusb#Re-use_the_pendrive &

https://unix.stackexchange.com/questions/216152/usb-disk-read-only-cannot-format-turn-off-write-protection

I do not like suggesting use dd as its nickname is Data Destroyer. If you select wrong drive, it totallly erases data. Check & double check you have correct drive. My system changes drive order on reboot with flash drive plugged in. So it may not be the same device, /dev/sdX when rebooted.

Zero out MBR and partition table, first sector only:
dd if=/dev/zero of=/dev/sdX bs=512 count=1