Thanks for your updates dizzy99,
At the beginning fo the file plugins\miwa-editor-mu\js\tinymce\tiny_mce_config.php, I try a relative include of the file wp-config.php
line5: @require_once('../../../../../wp-config.php');
It should load the necessary code to define the function user_can_switchedit().
Please check that the relative path is good, in your installation, to reach the file wp-config.php.
As a workaround you can comment out or remove these lines:
line38: if ( !user_can_switchedit() )
line39: $mce_buttons = str_replace('wp_help', 'wp_help,code', $mce_buttons);
They're useless in the plugin: I just tried to keep the original code.
Suleiman: your comment is carefully noted. And as you said, the current priority is to have this plugin working for other people than me :-)
Best Regards.