WooCommerce PDF Invoice

Hi Guys,

I recently switch my theme to Enfold.

I am ruining a woo commerce store with some plugins they all seem to be working apart from one:

WooCommerce PDF Invoice
https://docs.woothemes.com/documentation/plugins/woocommerce/woocommerce-extensions/pdf-invoice/

When it is activated I get a internal sever error notification when the ‘place order button’ is clicked.
Any ideas works fine with older theme

Settings are the same.