FIX: WP 4.9+ CodeMirror issues!

Here is a temporary fix for all of you who are having issues. Please note that I do not work for this developer of this plugin, I’m merely just trying to help out all of those who are affected by this and need a quick fix!
To remove the second code editor (wordpress editor), navigate to Users > your profile, and tick ‘Disable syntax highlighting when editing code’ on.

Next, add this to your functions.php file:

add_action('admin_head', 'my_custom_fonts');

function my_custom_fonts() {
  echo '<style>
#template {
    width: calc(100% - 208px) !important;
    float: left;
}
.CodeMirror {
    height: 100% !important;
}
#templateside {
    margin-top: 118px;
    height: 100% !important;
}
  </style>';
}

The above snippet will adjust the width & height of the code editor, aligning it nicely next to the file tree list.

The file tree list is messed up as well. The best you can do for this is turning it off in the code editor settings (the little cog), uncheck ‘Use File Tree’.

That will help fix a lot of the issues going on ??