Invalid value posted for Size

Is there a fix for the latest wordpress/woocommerce?

Everytime i use this plugin as oppose to the default dropdown i keep getting the error
‘Invalid value posted for Size‘ for my ‘size‘ attribute.

When trying to add a product to the cart with the variation that i have chosen. If i switch back to the default select dropdown behaviour of woocommerce it works perfectly. As soon as i switch to the template to use checkboxes i get the error.

Please help.
Thankyou