UI.browse_directory_dialog() , ScriptUI.query_string [...] must be strings [...] of strings and returns
CollisionFormatString ¶ [...] . It has to be a String.Format compatible format string
either be a string [...] , in other words, Selection [...] . In other words, one plugin
into a string, or a [...] into a string and return that string
containing strings [...] . If the string is empty [...] for this element as a string