Should be invoice linking issue with Payment Transaction. Need to check with data.

Hi,

Under the account module the "_render_qweb_pdf" function will called base don that function we get the Usererror
that checks whether the invoice type is an entry or not

if any(x.move_type == 'entry' for x in invoices):
                raise UserError(_("Only invoices could be printed."))

if the invoices move_type comes entry then that will generate the popup with the Usererror

Hope it helps