Wordpress Plugin Fix Required

My site uses a Formidable Form Pro Plugin with a Custom Field type called 'Image Cropper' that allows a site visitor to upload an image and crop it at the same time.

Upgrading to the latest version of Formidable Forms Pro results in no values being returned from the custom field type in any Formidable View.

The custom field type plugin is no longer supported by the author and has not been updated for the last 12 months.

I have created a test site with the latest version of Formidable Forms installed along with the cropper plugin.

At present the custom field does not work when attempting to add new entries (there is a Javascript error), and because of that I'm not able to add any records to replicate the problem with the views.

I also have a copy of the live site with the plugin working on the old version of Formidable Forms.

The goal is to identify why the plugin no longer works with the latest version of Formidable Forms and to fix it.