Troubleshooting
===============

This section lists common problems and possible solutions.
If you experience other problems or would like to add a solution for a problem
feel free to open an issue in our
`Github project <https://github.com/linux-automation/usbmuxctl/issues>`__
or send us an email to info@linux-automation.com.

Permission denied when accessing the USB-Mux
--------------------------------------------

**Problem:** The control software outputs an "Access denied" message
and does not find the specified USB-Mux.

In the following example a user tries to access the USB-Mux without
previously installing the udev-rule:

.. code:: text

   $ usbmuxctl --serial 22 status
   Access denied while checking serial number for device: 1-5.1
   Failed to connect to device: Failed to find the defined USB-Mux

To fix this issue either run the tool as `root` (e.g. using ``sudo``)
or setup an udev-rule that grants access to your user.
The chapter :ref:`Using as non-root user<non-root-use>` for setup
instructions.
Make sure to reload the udev config, re-attach the device and re-login
into your device after installing the rule.
Also make sure that the group name specified in the udev rule appears
in the output of the ``groups`` command:

.. code:: shell

    $ groups
    … plugdev …