usb-creator-gtk does not work: "Installation Failed"

Status changed to 'Confirmed' because the bug affects multiple users.

Similarly for me, in trusty as well.

Terminal output of running usb-creator-gtk doesn't say much either:

$ usb-creator-gtk
/usr/lib/python3/dist-packages/usbcreator/frontends/gtk/frontend.py:38: PyGIDeprecationWarning: Since version 3.11, calling threads_init is no longer needed. See: https://wiki.gnome.org/PyGObject/Threading
  GObject.threads_init()
$

Commenting out the exception-swallowing try-except in gtk/frontend.py install(), I get a better error message:

/usr/lib/python3/dist-packages/usbcreator/frontends/gtk/frontend.py:38: PyGIDeprecationWarning: Since version 3.11, calling threads_init is no longer needed. See: https://wiki.gnome.org/PyGObject/Threading
  GObject.threads_init()
Traceback (most recent call last):
  File "/usr/lib/python3/dist-packages/usbcreator/frontends/gtk/frontend.py", line 655, in install
    allow_system_internal=self.allow_system_internal)
  File "/usr/lib/python3/dist-packages/usbcreator/backends/udisks/backend.py", line 312, in install
    source = self.helper.MountISO(isofile)
  File "/usr/lib/python3/dist-packages/dbus/proxies.py", line 145, in __call__
    **keywords)
  File "/usr/lib/python3/dist-packages/dbus/connection.py", line 651, in call_blocking
    message, timeout)
dbus.exceptions.DBusException: org.freedesktop.DBus.Python.UnicodeDecodeError: Traceback (most recent call last):
  File "/usr/lib/python3/dist-packages/dbus/service.py", line 707, in _message_cb
    retval = candidate_method(self, *args, **keywords)
  File "/usr/share/usb-creator/usb-creator-helper", line 270, in MountISO
    popen(['mount', '-o', 'loop', device, ret])
  File "/usr/lib/python3/dist-packages/usbcreator/misc.py", line 170, in popen
    out, err = process.communicate()
  File "/usr/lib/python3.3/subprocess.py", line 921, in communicate
    stdout, stderr = self._communicate(input, endtime, timeout)
  File "/usr/lib/python3.3/subprocess.py", line 1570, in _communicate
    self.stderr.encoding)
  File "/usr/lib/python3.3/subprocess.py", line 846, in _translate_newlines
    data = data.decode(encoding)
UnicodeDecodeError: 'ascii' codec can't decode byte 0xd0 in position 33: ordinal not in range(128)

This led to identifying the problem: my .img file (actually, my entire download folder) is in a directory containing UTF-8 characters. Simply moving the .img file to a path containing no Unicode allowed usb-creator-gtk to create an image from it.

Changing the locale itself didn't help, except that running in C locale made it crash even earlier.

Actually, that wasn't enough, still investigating.

Ok, the problem now was that all the loop devices were already used. Umounted them all, and it does indeed progress now (at "copying files" now).

It prevents the package (or a dependent one) from functioning correctly at all.

I had the same issue, the problem was that the localized name of the "Downloads" folder contained non-ascii characters (Stažené). As workaround, move the .iso to /tmp or ~ (if that one is ascii-clean) and select it using the "other" button.

If it fails nevertheless , you are having another issue than me.

Confirming Václavs conclusion in post #7. Moving the ISO to a folder that does not contain local characters (Swedish åäö in my case), "solves" the problem.

@eudoxos (Václav Šmilauer) yes, your answer #7 was the problem for me too, thx a lot yout work around!! :)