The PDF file is actually perfectly valid Postscript. The problem lies somewhere between your PDF viewer and your printer software. It's not something we can "fix" in any way. Slight differences in the Postscript would make the PDF work on a reader and break it on another. That's the downside of having to issue bilingual invoices for legal reasons :(
You can always get it and print it as an HTML document. Go to My Subscriptions and click on the first "Invoice" button (the one that has an eye icon). This should open a new page with the HTML copy of the invoice that you can print like any other web page.
Nicholas K. Dionysopoulos
Lead Developer and Director
🇬🇷Greek: native 🇬🇧English: excellent 🇫🇷French: basic • 🕐 My time zone is Europe / Athens
Please keep in mind my timezone and cultural differences when reading my replies. Thank you!