serial port in chirp

I’m unable to program my kenwood tm-g707 on Ubuntu with Chirp and I need help! I get this could not configure port (5 'input/output error')

 kg4rxs@kg4rxs-Latitude-E6420:~$ sudo chirpw
[sudo] password for kg4rxs: 

(process:6302): Gtk-WARNING **: Locale not supported by C library.
    Using the fallback 'C' locale.
ERROR: --- Exception Dialog: Could not configure port: (5, 'Input/output error') ---
ERROR: Traceback (most recent call last):
  File "/usr/lib/python2.7/dist-packages/chirp/ui/mainapp.py", line 682, in do_download
    timeout=0.25)
  File "/usr/lib/python2.7/dist-packages/serial/serialutil.py", line 180, in __init__
    self.open()
  File "/usr/lib/python2.7/dist-packages/serial/serialposix.py", line 298, in open
    self._reconfigure_port(force_update=True)
  File "/usr/lib/python2.7/dist-packages/serial/serialposix.py", line 330, in _reconfigure_port
    raise SerialException("Could not configure port: %s" % msg)
SerialException: Could not configure port: (5, 'Input/output error')

ERROR: ----------------------------

The most common cause is that the user(s) do not have permission to use the serial-USB connection. Permission must be established for the user. There is much more on this common issue in Linux or Ubuntu wikis and support websites.

Start a terminal session and enter this command :

sudo gpasswd --add ${USER} dialout

After executing the command, check that it worked with:

groups ${USER}

The user name will be followed by a list that includes dialout. Dialout means permission for the TTY set that includes serial and USB connections.