.. _hello_world:

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

.. Error:: 
    **Q**: Why do I see the following error when running ``./adbforwarder/ADBForwarder``?

    .. code-block:: text

        Platform: Linux
        Unhandled exception. SharpAdbClient.Exceptions.AdbException:
        The adb process returned error code 255 when running command start-server
            at SharpAdbClient.AdbCommandLineClient.RunAdbProcess(String command, List`1 errorOutput, List`1 standardOutput)
            at SharpAdbClient.AdbCommandLineClient.StartServer()
            at SharpAdbClient.AdbServer.StartServer(String adbPath, Boolean restartServerIfNewer)
            at ADBForwarder.Program.Main()
        Aborted (core dumped)

**A**: This usually means ADB is not installed or the server is in a broken state. Try the following steps:

1. Check if ADB is installed:

   .. code-block:: bash

      adb version

   If the command is not found, install ADB:

   .. code-block:: bash

      sudo apt update
      sudo apt install adb

2. Kill and restart the ADB server:

   ADB might have a zombie or corrupted background process. Run:

   .. code-block:: bash

      adb kill-server
      adb start-server

After restarting the ADB server, try running ``./adbforwarder/ADBForwarder`` again.

.. Error::

    **Q**: If you see “Graphics error” TODO 

**A**: TODO 

.. note::

    If you build ALVR from source, make sure the host firewall is not blocking ports 9944, 8082, and 9942.

    - Disable and re-enable the firewall:

    .. code-block:: bash

        sudo ufw disable
        sudo ufw enable

    - The firewall rule should be set automatically during the default ALVR dashboard installation. If you miss this step, you can add it manually by clicking ``Installation`` → ``Add firewall rules`` in the ALVR dashboard.