cannot see whats generate

Hi,

today and without make any update to any plugin,

when i try to create an invoice, i see only a blank page “The plugin could not be loaded”, althoug i see that the number of the invoice is been created.

I tried with many different browsers, still the same.
i tried from my mobile, and i can see the invoice.(?)

https://www.beeramatistirio.gr/wp-admin/admin-ajax.php?action=generate_wpo_wcpdf&document_type=invoice&order_ids=17330&_wpnonce=1c4c08c212

Have deleted all cookies but still the same.
Have turned on debug mode, and still the same.

Any help would be apreciated.

The page I need help with: [log in to see the link]