Reference plugin errors

I want to add reference output to a simple page. I’ve tried 3 approaches and I get a different error for each.

Versions
Omeka 2.7.1
Reference 2.4.3

My 3 approaches:

  1. I added a shortcode to a simple page
[reference]
[reference slug=date skiplinks=true headings=true raw=false]

and got this error: Illegal string offset ‘view’ in /plugins/Reference/ReferencePlugin.php on line 351

  1. Added the following code to /SimplePages/views/public/page/show.php
echo $this->reference();

and I get this error: Object of class Reference_View_Helper_Reference could not be converted to string

  1. Added the following code to /SimplePages/views/public/page/show.php
$slug = 'item-type-metadata-state';
$references = $this->reference()->getList($slug);
echo $this->reference()->displayList($references, array(
    'skiplinks' => false,
    'headings' => false,
    'strip' => false,
    'raw' => false,
)); 

and I get no output and no error.

I’m not sure what the problem is. I am using Reference on another Omeka install (v. 2.7), the same version of PHP is installed (7.2), and all works as expected. Is the plugin not compatible with Omeka 2.7.1? Or should I be doing something different ?

The example provided in the plugin’s README for #3 is missing ‘slug’ in the options array.

The following modification works for me:

$slug = ‘subject’;
$references = $this->reference()->getList($slug);
echo $this->reference()->displayList($references, array(
‘slug’ => $slug,
‘skiplinks’ => true,
‘headings’ => true,
‘strip’ => true,
‘raw’ => false, ));