I created a bootable USB key and needed to format the key so that others could use it again.
Using the format option (see image below) in the KDE file environment, I got this error:
This partition cannot be modified because it contains a partition table; >please reinitialize layout of the whole device. (udisks-error-quark, 11)
I then tried to use the gparted tool. You can install it easily using
dnf install gparted
and starting the tool as sudo (sudo gparted).
You can select the partition you want to change in the top right corner (see image here below for a snapshot of the interface).
You can check the name of the partition using the linux command
Once the USB stick is selected, click on the “Device” tab > Create Partition Table.
However, there was several errors telling me that the partition could not be changed.
So, I then tried the mkfs linux command line tool:
sudo umount /dev/sdc1 sudo mkfs.ext4 /dev/sdc1
This seemed to work but wait a minute: the disk is 1.7Gb as if it was not really cleanup from the fedora bootable partition. I know that the USB disk is actually 16Gb large. So 13G is unallocated.
Somehow, going back to the KDE environement (image at the top), I click the format option, umount / mount and now I can see the 16G. This can be check visually using gparted (image below).