If you are using theme_get_settings, such as: $value = trim(theme_get_setting('my_setting')); Then in your code editor you will also be seeing undefined  function 'theme_get_setting'.  This function has been deprecated for some time.   Instead, you need to use Passing the theme.manager and theme.initialization services to theme_handler constructor as optional parameters is deprecated. These parameters are also mandatory. $theme_handler = \Drupal::service('theme_handler');Get...

The starting point is to read through and follow the notes outlined on the ejabberd site regarding adding database schema.  The purpose of this documentation is to clarify where the files were located for me. The schema files can be found in ejabberd priv directory.  To find the priv directory, use the find command find / -name priv -type dInitially, the directory I found based on the...