Based on your report, it appears that the usb device has an invalid partition table.
A work around is to copy your data to another device, write a new partition table to the usb device, and then restore your data back to the usb device. A similar bug has been reported: Verbatim USB stick crashes gParted https://bugs.launchpad.net/ubuntu/+source/gparted/+bug/710696 -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/695341 Title: Gparted close when mount usb device -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
