Tabledrag with Field Groups not working

Currently using Drupal 8.3.0-rc2, Display Suite 8.x-3.0-beta1 and Field Group 8.x-1.0-rc6. When trying to drag a Field Group on the manage display tab, it throws a JS error:

Uncaught TypeError: Cannot read property 'relationship' of undefined
    at Drupal.tableDrag.updateField (js_MVCuqoJ-vXm_ilLQ8XwCF9UtB9qdn5SC5ye4ma-OmeI.js:2265)
    at Drupal.tableDrag.updateFields (js_MVCuqoJ-vXm_ilLQ8XwCF9UtB9qdn5SC5ye4ma-OmeI.js:2244)
    at Drupal.tableDrag.dropRow (js_MVCuqoJ-vXm_ilLQ8XwCF9UtB9qdn5SC5ye4ma-OmeI.js:2084)
    at HTMLDocument.<anonymous> (js_MVCuqoJ-vXm_ilLQ8XwCF9UtB9qdn5SC5ye4ma-OmeI.js:1551)
    at HTMLDocument.dispatch (js_MVCuqoJ-vXm_ilLQ8XwCF9UtB9qdn5SC5ye4ma-OmeI.js:3)
    at HTMLDocument.r.handle (js_MVCuqoJ-vXm_ilLQ8XwCF9UtB9qdn5SC5ye4ma-OmeI.js:3)

In field_group/includes/field_ui.inc line 189, I changed the line to:
'#attributes' => array('class' => array('field-group-type', 'field-region')),

And by adding the 'field-region' class I was again able to drag and drop the field group.

Will be uploading a patch shortly. Probably needs more testing to make sure this doesn't break other stuff. :)